"Why, and what are the two main branches of buddhism (Theravada and Mahayana) that contradicts one another?"
There are some minds are being confused by the existence of 'Theravada' and 'Mahayana' buddhism, where the teachings and practices are contradicting against one another, and are puzzling towards what and why there are the two contradicting branches/teachings/practices of Theravada and Mahayana buddhism, not to say, there were/are many other forms/versions/sub-branches of 'buddhism' under different names and forms that kept popping-up and existing here and there.
The presence of such doubt towards the many existing teachings and practices of 'buddhism' under many different names and forms, indicates the sprouting and growing process of 'the seed of dhamma' in the mind.
Most minds would perceive 'the presence of doubt', or 'I don't know and don't understand many things', as a form of stupidity, or weakness, or shortcoming, or negativity.
The presence of doubt and the capability to be doubting the truth of something or everything, as well as coming in contact with undesirable/unpleasant/disagreeable painful sorrow and suffering, on top of coming in contact with the fleeting impermanent changes in everything, especially in the desirable/pleasurable/agreeable names and forms, are the upmost precious elements that initiate and activate the path of self inquiry and self realization towards knowing Thyself.
It doesn't mean that one should be continuously undergoing all kinds of evitable unnecessary painful suffering and difficulties in order to be liberated from ignorance, or to attain direct self realization towards the universal dhamma/truth of everything.
That is what the buddhism teachings and practice is about, being aware of the presence of ignorance and doubt or unknown and uncertainty, and be initiated to be inquiring towards the truth of everything without blind-practicing or blind-propagating, not to say, none should be believing/following/glorifying/worshiping towards anyone or anything, including the existing available teachings of buddhism, or the enlightened minds/buddhas that had/have attained direct realization towards the universal dhamma/truth of Selflessness and Non-self, including Siddhartha Gautama buddha himself, where the universal dhamma and buddhism don't belong to anyone or anything, not to say, they didn't come from any enlightened minds/buddhas that had/have realized the universal dhamma/truth, including Siddhartha Gautama buddha himself, where there were, have been, and will be many others enlightened minds/buddhas before, during, and after the selfless impermanent limited conditional and non-self existence of Siddhartha Gautama buddha himself, whom we perceived and recognized and taken as the all time teacher of dhamma, or buddhism.
There are many minds aren't even aware of the existence of not only some obvious differences, but even some distinctive contradictions against one another in the teachings and practices of these two branches of buddhism.
There were/are many minds merely blind-believing, blind-following, blind-glorifying, blind-worshiping, and blind-propagating the teachings and practices of buddhism, as they weren't/aren't aware of the real meanings of the teachings and practices due to under the presence of the veil of ignorance, where they thought and believed that buddhism is merely a form of religious or spiritual practice just like many other kinds of religions and spiritualities in the world of many diversities, where there were/are many minds needed to hang onto some kind of 'super extraordinary all powerful almighty entity', or 'refuge', or 'floating objects', while dealing with the exhausting process of inevitable ceaseless life maintenance of feeding hunger and thirst and eliminating waste products, physical/mental/emotional fatigue, exhaustion, or restlessness, hormonal/muscular and cardiovascular-fitness/strength/stamina/energy level/mobility/ability fluctuation and imbalance, many kinds of painful sorrow and suffering, doubts, unknown, uncertainty, insecurity, fear, cruelty, selfishness, possessiveness, greed, discontentment, anger, hatred, jealousy, unjust, corruption, discrimination, invasion, intrusion, occupation, fighting, violence, limitations, conditions, situations, obstacles, difficulties, hardships, impermanent changes, accidental events, natural disasters, hurts, damages, losses, illness, injury, old age, weakness, disability, powerlessness, vulnerability, decay and death, on top of all kinds of undesirable/disagreeable/unpleasant experiences, affairs, relationships, ties and connections, interactions, and activities, as well as being disappointed repeatedly by the momentary fleeting sense of satisfaction, excitement, goodness, righteousness, happiness, joyfulness, meaningfulness, positiveness, success, accomplishment, and so on.
Some minds might be aware of the existence of the obvious differences/contradictions in the different lineages/branches/schools of buddhism, and even within the teachings of the same lineage/branch/school, but they don't bother to be questioning, inquiring, investigating, and finding out the truth of all THAT, as there have been some 'justifications' here and there to justify all THAT, to silent the questioning of the doubting mind, because the minds themselves also don't understand and don't know how to answer the questions coming from the doubtful minds.
There is neither right nor wrong, as all THAT exist for the different minds functioning under different degrees of ignorance.
Just like the existence of real fruit juice (with only fresh fruits and natural sweetness) and artificially flavouring and sweetened fruit juice (with or without certain amount of fresh fruits), they might look alike, but they are two very different things. Although there are many minds might prefer the taste and texture of the artificial fruit juice for some reasons. Just like there are many minds would prefer the many different forms/types/versions of 'modified/moderated/manipulated buddhism' than the 'buddhism as it is'. That is the freedom of all minds for what they want and don't want.
Similarly, Theravada buddhism and Mahayana buddhism might have the same name of buddhism, but the teachings and practices are two different things.
Just as the universal truth of all and everything, the universal dhamma, or the teachings and practice of Buddhism, is only one, and always one.
Just as yoga is only one, and always one, but there are also the manifestation of the different lineages/paths of yoga to suit different minds under different personalities, and that are functioning under the influence of different degrees of ignorance.
This is not about one is real and the other is false, or one is authentic/pure and the other is non-authentic/impure, or one is better and the other is less good.
It is about what the minds really, really, really want?
Many minds only want to have a 'super extraordinary all powerful almighty entity', or 'refuge', or any kind of 'floating objects' to hang onto, while enjoying all kinds of momentary fleeting pleasurable enjoyments/goodness/joyfulness/meaningfulness/positiveness/righteousness/togetherness/powerfulness/and etc as much as possible, as much as they can. Then the 'buddhism as it is' (Theravada) will appear to be too difficult and inconvenience and uninterested, or even useless, to them. Where the engagement in the Mahayana buddhism might can give them the momentary fleeting sense of comfort, hope, refuge, mental and emotional support, community support, goodness, righteousness, positiveness, meaningfulness, joyfulness, purposefulness, powerfulness, togetherness, and so on, to deal with all kinds of ignorance, restlessness, madness, and undesirable/unpleasant/disagreeable impermanent changes/activities/limitations/conditions/situations/affairs/relationships/ties and connections/interactions that exist in themselves and in the surrounding environment in this world of many diversities that doesn't belong to anyone or anything.
The engagement in Theravada 'buddhism', not to say, Mahayana 'buddhism', doesn't necessarily liberate the minds from ignorance and the by-products of ignorance, unless the minds work diligently and determinedly on eliminating the idea of 'I' and egoism, and turning the outgoing tendency of the mind inward, and inquire towards the truth of all and everything diligently, including towards the truth of all kinds of teachings and practices of the Theravada 'buddhism' that is the closest to the root of 'buddhism as it is', as well as the Mahayana 'buddhism' that is 'being dominated by' and 'not different from' any kind of worldly egoistic cultural, religious, spiritual, communal, tribal, or even, commercial, national, and political ideas, values, practices, aspirations, and visions, under the influence of the natural veil of ignorance (The egoistic impure restless modification of the mind occupied by the idea of 'I'/the ego, egoism, impurities, and restlessness).
This doesn't mean that Mahayana 'buddhism' is non-authentic buddhism.
Like the existence of all kinds of 'imaginary friend', or 'super extraordinary all powerful almighty entity', or 'temporary refuge', or 'floating objects' (all kinds of cultural, religious, spiritual, tribal, communal, family, national, political, economical, commercial, or philosophical ideas, values, practices, aspirations, and visions) in the world of ignorance and suffering, they all come with certain 'good intention', or 'positive motivation', or 'goodwill' to create and empower some kind of temporary comfort, hope, refuge, mental and emotional support, community support, goodness, righteousness, positiveness, meaningfulness, joyfulness, purposefulness, powerfulness, togetherness, and so on, amid all kinds of evitable and inevitable painful suffering and undesirableness/disagreeableness/unpleasantness, in order to keep everyone and everything under certain 'order', and they are not perfect, and they have certain inevitable hurtful and destructive side-effects that will eventually affect, hurt, or damage all and everyone and everything in the long term, directly or indirectly, unwittingly and unintentionally.
Just like many parents/teachers/leaders were/are teaching/disciplining/controlling the children/students/people to behave in certain way and not in certain way, where the parents/teachers/leaders create certain kind of threatening story telling with painful punishment as well as tempting pleasurable rewards in return depending on their behavior. This is leading towards hurtful destruction towards all and everyone and everything in many ways, even if the children/students/people might behave 'accordingly' to avoid painful punishment and to receive pleasurable rewards from the parents/teachers/leaders, but not because they have the clarity of thinking and correct understanding of mental and emotional independence to be behaving in certain way and not in certain way, out of their own conscious freewill/understanding/choice/initiative/self control, as they were/are never being guided by the parents/teachers/leaders to become mentally and emotionally independent, because the parents/teachers/leaders don't want that, but they only want to 'control' everyone and everything to be and not to be in certain way.
Regardless of whether there is engagement in Theravada or Mahayana 'buddhism' in any areas or regions, not all minds are free from the influence of ignorance, where there were/are contamination, manipulation, misconduct, abusive behavior, exploitation, possessiveness, anger, hatred, jealousy, discrimination, bully, or violence existing in anywhere and everywhere, due to the presence of the veil of ignorance in the minds.
That is why the world is what it is, in a growing state of madness and chaos and violence, that could have been avoided, if the minds have not been being hammered and limited and conditioned by all kinds of worldly egoistic impure ideas, values, practices, aspirations, and visions, that empower the veil of ignorance, that empower the idea of 'I', egoism, impurities, and restlessness, that hinder mental and emotional independence, that hinder clarity of thinking and correct understanding, in the pursue of prosperity, success, goodness, righteousness, positiveness, joyfulness, meaningfulness, and/or 'peace and wisdom and compassion', but not really.
Although there is nothing wrong and it is very good indeed to encourage wisdom and kindness and peace in the minds, however, that doesn't free the minds from being determined and disturbed by what they think and believe as unkindness, selfishness, negativeness, unhappiness, meaninglessness, joylessness, undeserving, unpleasantness, undesirableness, disagreeableness, badness, and wrongfulness, unless the minds attain direct realization towards the truth of Selflessness and Non-self, through meditation and self inquiry and self realization.
Some minds genuinely want to be free from ignorance and the by-products of ignorance (the mind perception/cognition towards all kinds of evitable and inevitable physical/mental/emotional suffering), and to attain direct realization towards the truth of everything (wisdom/absolute knowledge), and realize unconditional peace, in this present moment, while still existing/living/functioning (not upon death, or after the end of this life existence). Then 'buddhism as it is' or 'yoga as it is', is what they are looking for.
Just as there are many children don't like the taste of medicines as they are, and might not be understanding towards preventing evitable illness or injury (buddhism as it is), but the medicines with added artificial flavouring and sweetness (the many modified/moderated/manipulated forms/versions of buddhism) might do the trick for the children to take them without much resistance, although, they might develop addiction or craving towards the artificial flavouring and sweetness only, but have no interest at all towards the medicine as it is, as well as to be learning and understanding how to prevent or minimize from contracting unnecessary evitable illness or injury.
Even though being tricked to take the medicines due to the added artificial flavouring and sweetness, there will still be the same effects coming from the medicines. But the recovering from this particular illness or injury, doesn't stop the children from getting sick or injury repeatedly. Such as the minds are being encouraged to be kind and generous and unselfish, to perform charity and wholesome activity regularly, and not performing any harmful activity, that are benefiting oneself and others and the surrounding environment, even if these practices are being carried out blindly, however, that also doesn't guarantee that the minds won't be determined or disturbed by what they think and believe and recognize as bad and wrong and undeserving, or unpleasant and disagreeable and undesirable, or won't be generating actions/reactions/activities/behaviors that will cause certain hurtful destructive effects unto oneself and others and the surrounding environment directly and indirectly, under certain circumstances, conditions, and situations, either wittingly or unwittingly.
There was only the universal dhamma, or buddhism as it is, where there were neither 'Theravada' nor 'Mahayana' in the beginning, not to say, the many other creations of 'the different forms/types/versions of buddhism' under different names and forms (different lineages/branches/communities/cultures) that are being mixed with their own different particular worldly egoistic cultural, religious, spiritual, communal, tribal, regional, national, commercial, or political ideas, values, practices, aspirations, and visions, that are being referred as one of the branches of 'Buddhism', that were/are existing, under specific cause, under certain circumstances, conditions, and situations, and under the different manipulation of the many different minds that didn't/haven't attain(ed) direct realization towards the truth of Selflessness and Non-self. And there is nothing wrong with that, due to the natural veil of ignorance in the minds.
Under the influence of the veil of ignorance, the minds that were/have been engaging in buddhism, and were/are practicing buddhism, but they didn't/haven't yet attain(ed) direct self realization towards the truth of Selflessness and Non-self due to the presence of the veil of ignorance, where they thought and believed that 'the buddhism as it is' was unreachable or impossible for them, and hence, they thought and believed that they themselves and many other minds needed a 'different type/version/approach of buddhism teachings and practices' that will be either much easier, or more approachable, or less intimidating for most minds. And there is nothing wrong with that, and that is a common and natural behavior of the minds that are functioning under the influence of the veil of ignorance.
The buddhism practitioners were practicing 'buddhism as it is', neither Theravada nor Mahayana, not to say, Zen buddhism, or Japanese buddhism, or Tibetan buddhism, or Chinese buddhism, and etc, before the beginning of the existence/creation of the different modified/moderated/manipulated forms/types/versions of buddhism in the world, in the different areas and regions under the different cultural, spiritual, religious, tribal, communal, national, commercial, and political influences.
The name of 'Theravada' buddhism that didn't (need to) exist before, but then it has been existing, as there is a need to distinguish 'the buddhism as close to the root as it is' from all the other many different modified/moderated/manipulated forms/types/versions of buddhism that were/are no longer what buddhism as it is, throughout the prolonged impermanent changes.
The universal dhamma/truth cannot be contaminated by anyone or anything, but the 'dhamma' or all kinds of teachings and practices of 'buddhism' that exists under certain names and forms can be and has been ceaselessly being manipulated or contaminated in many ways, naturally and inevitably.
The teachings and practice of buddhism was, and is, the path of meditation, purification and silence of the egoistic impure restless modification of the mind to remove the natural veil of ignorance, self inquiry, and self realization towards knowing Thyself, or realizing/knowing the universal dhamma/truth of Selflessness, Impermanence, Limitation, Conditional, and Non-self in all and everything, governed by the nature's law of cause and effect. It is practicing, inquiring, realizing, and disseminating the universal dhamma as it is.
There were/are no rituals, or offerings, or sacrificing, or penance, or judgments, or punishments, or devotions, or believing, or following, or glorifying, or worshiping, or the impersonate 'xxx' existence, or 'the almighty creator/authority/controller/judge of the universe'.
There is merely the universal dhamma (Everything that the mind perceives/comes in contact with and the sufferer/enjoyer/thinker/knowledge seeker/practitioner/observer/inquirer/knower/seer/hearer/smeller/taster/senser, or the conscious perceptive cognitive intellectual emotional thinking and acting faculty/mind of the conscious sentient living organisms under the presence and absence of the limited conscious awareness under different impermanent states of consciousness/semi-consciousness/unconsciousness that is highly essential for maximal survival and maintaining/balancing/replenishing/regenerating the selfless impermanent limited and conditional life existence and function of the body and mind that is non-self, that doesn't even belong to the body and mind itself, until the body and mind ceased functioning and existing). It is not a form of spirituality, not to say, religion.
Meanwhile, if looking at the teachings, practices, or activities under the name of Mahayana buddhism, then very obviously, one will know that it was/is a sub-creation of 'buddhism', where the non-spiritual/non-religious/non-rituals/non-offerings/non-worshiping/non-glorifying/non-devotional 'buddhism as it is' was/is being transformed/modified/moderated/manipulated into a form of cultural, religious, and spiritual teachings and practice, of performing all kinds of rituals and offerings, or penance and worshiping, asking for all kinds of blessings and protections from the many different 'buddhas' under different names and forms, being introduced and performed by the minds that were/are still functioning under the influence of the veil of ignorance, for their own particular reasons or agendas, to suit themselves and the other minds that were/are still functioning under the influence of the veil of ignorance.
It is understandable that why buddhism has been widely being referred as a form of cultural, religious, or spiritual teachings and practice because of the existence of the different types/versions of modified/moderated/manipulated 'buddhism'.
The students/practitioners of buddhism as it is, have no identification as 'buddhist', or 'the buddhism practitioner', or 'the follower of different buddhas', or 'the disciple of specific lineage of buddhism', and etc.
The minds that think and believe and identify themselves as 'buddhist', or 'the buddhism practitioner', or 'the follower of different buddhas', or 'the disciple of specific lineage of buddhism', and etc, they have been being conditioned by the worldly egoistic cultural, religious, spiritual, tribal, communal, or even, commercial, national, and political ideas, values, beliefs, practices, aspirations, and visions towards the existence of an eternal permanent independent infinite individual identity of an immortal spirit/soul/consciousness of an unique ancient identity, that is residing in the body and mind or in any kind of names and forms, that is, and has been, undergoing countless beginningless and endless reincarnations/rebirths reincarnating under different separate momentary mortal life existences, transitioning under countless realms/spheres/worlds/realities in accordance to the boundless and endless generation and accumulation of inexhaustible good/bad/neutral karma that keep bringing forward to the next and next endless reincarnations/rebirths to reap the inexhaustible never ending boundless 'karma', either by own choice (if reached 'the state of enlightenment') choosing to come back under a specific particular name and form into the world of impermanent momentary mortal life existence(s) for continuing one's unfinished spiritual, or religious, or communal, national, and political duty/responsibility/legacy/vision/aspiration/ambition, or not by own choice (if not reaching 'the state of enlightenment') unwittingly and reluctantly keeps coming back into the world of mortal impermanent momentary life existences repeatedly and restlessly transitioning under different realms/spheres/worlds/realities, to reap the boundless and endless inexhaustible good and bad and neutral karma.
All THAT is completely swaying away from the universal dhamma/truth of Selflessness and Non-self, that has to be self realized directly by the minds themselves under a purified calmed and quiet one-pointed state of mind, where there is not any eternal permanent independent infinite self existence of an immortal individual spirit/soul/consciousness existing in any names and forms regardless of living organisms or non-living objects, where there is neither past nor future continuous separate different life existence of an eternal permanent independent infinite self existence of an immortal individual spirit/soul/consciousness that doesn't exist, to be residing in countless different body and mind, undergoing countless 'reincarnations/rebirths reincarnating under different realms/worlds/spheres/realities' in accordance to the past continuous generation and accumulation of boundless inexhaustible good/bad/neutral karma, that belong to an eternal permanent independent infinite self existence of an immortal individual spirit/soul/consciousness, that doesn't exist.
Under the teachings, practices, and activities of certain buddhist organization under the name of 'buddhism', compassion is widely being referred as "慈悲" that is about, "Give happiness/pleasurable enjoyments and conveniences to others and remove unhappiness/painful sorrow and suffering and difficulties from others", or "I will sacrifice myself to suffer for other beings or to lessen the suffering of other beings", or "If one attains enlightenment, then all one's ancestors will also be uplifted to higher realms/worlds/spheres/realities", while at the same time, it also propagates part of the buddhism teachings about, "None can interfere with the karma of one another, and none can replace the suffering for one another. One reaps the seeds (karma) that one sows. Not even the parents can swap themselves to suffer for their suffering child." These teachings are obviously contradicting one another.
And because of the existence of such contaminated and manipulated teachings and practice under the name of 'buddhism', there was/is a need for the name of 'Theravada buddhism' to distinguish 'buddhism as it is' from all the other forms/types/versions of 'buddhism' that were/are no longer buddhism as it is - that swayed away from the universal dhamma/truth of Selflessness and Non-self.
It doesn't mean that there is no contamination in the teachings and practices of Theravada buddhism. Due to the ignorance in the minds, all kinds of teachings and practices that exist under certain names and forms will be contaminated and manipulated more or less, or here and there, however, the teachings and practices of Theravada buddhism were/are being preserved as close as possible to the root of buddhism as it is, as taught by Siddhartha Gautama buddha, that was/is emphasizing on non-believing/non-following/non-glorifying/non-worshiping/non-blind practicing/non-blind propagating, silence/stillness of the restless modification of the mind, to prepare the mind for vipassana, or insight, or self inquiry and self realization towards the truth of all and everything - Selflessness, Impermanence, Limitation, Conditional, and Non-self, governed by the nature's law of cause and effect.
For some reasons (under the influence of ignorance and egoism that gives rise to the sense of separateness and duality of 'I' and 'the others', superiority and inferiority, selfishness and unselfishness, and etc), Theravada buddhism (小乘) has been being referred as 'inferior', or even, 'non-compassionate' or 'selfish' form of buddhism, that focusing on "The annihilation of the veil of ignorance in oneself", while Mahayana buddhism (大乘) has been being referred as 'superior' and 'compassionate', or a form of 'unselfishness' or 'self sacrifice', that focusing on "Letting all the others to attain salvation before me. I will be the last one to leave the world of suffering. I will keep coming back again and again to help all the others to attain salvation until there is none remaining in the world of suffering, but me, and then I will go."
Inquire towards the truth of such reference, and one will know what is the truth behind this type of reference. One doesn't need to be highly intelligent or knowledgeable, but only some basic universal common sense to inquire towards the truth of such reference.
This only shows that 'Saving others without saving oneself first', or 'Hoping that there is peace and harmony or wisdom and kindness in the world but without peace and harmony or wisdom and kindness in oneself', or 'Helping all the others to be free from ignorance but oneself is not free from ignorance', doesn't work at all.
That is why the highly importance of "Thus have I heard" in front of all teachings that are related to buddhism.
Even so, there is neither right nor wrong, neither good nor bad about Mahayana buddhism is swaying away from what buddhism is about, where they emphasized on the cultural/religious/spiritual existence of an eternal permanent independent infinite existence of an immortal individual spirit/soul/consciousness undergoing ceaseless endless reincarnations/rebirths under countless different separate life existences transitioning under different realms/worlds/spheres/realities in accordance to the ceaseless generation and accumulation of boundless inexhaustible good/bad/neutral karma that needed to be carrying forward to the next and next endless different separate life existences, in order to justify many things that are unknown, undesirable, unpleasant, disagreeable, unjust, undeserving, painful, disappointing, abusive, exploiting, bullying, violent, intrusive, invasive, and so on, to the minds, that might or might not give rise to certain degrees of momentary comfort, or hope, or refuge, or resting point, or escape to the minds to deal with all THAT.
The ceaseless restless births and deaths of ceaseless and countless thought after thought ceaselessly arising, changing, and passing away, of the restless thought current/activity/input and output processing (what the many minds referred as 'ceaseless reincarnation/rebirth in countless different separate life existences') transitioning under different impermanent states of mind/conditions of the physical body/affairs and experiences in the surrounding environment (what the many minds referred as different 'realms/worlds/spheres/realities') governed by the nature's law of cause and effect (what the many minds referred as the inexhaustible boundless 'good/bad/neutral karma'), is merely the reflection of the ceaseless restless selfless impermanent limited and conditional changes in the body and mind that is non-self, that doesn't even belong to the body and mind itself, where transitioning under the different realms are reflecting the mind perception towards the different impermanent states of mind while perceiving the physical body and the surrounding environment of all kinds of names and forms, that are also selfless, impermanent, limited, conditional, and non-self, that ceaselessly changing, decaying, and disintegrating, governed by the attributeless indiscriminate nature's law of cause and effect (that was/is being misinterpreted/misunderstood/propagated as the belief of the ceaseless boundless inexhaustible good/bad/neutral karma that needed to be kept carrying forward to the next and next endless different separate life existences in different realms/worlds/spheres/realities of an eternal permanent independent infinite existence of an immortal individual spirit/soul/consciousness, that doesn't exist.)
'Ceaseless and countless births and deaths transitioning under different realms governed by nature's law of cause and effect' are ceaselessly happening in this present moment in this selfless impermanent limited conditional existence and function of the body and mind that is selflessly undergoing ceaseless and endless impermanent changes (until the body and mind ceased functioning and existing), that is non-self, that doesn't even belong to the body and mind itself, not to say, that doesn't belong to anyone or anything (what the many minds believe as an eternal permanent independent infinite existence of an immortal individual spirit/soul/consciousness that resides in the body and mind, that doesn't exist.)
'Ceaseless and restless countless births and deaths of countless names and forms transitioning under different realms in NOW' is about 'The ceaseless impermanent changes of the countless selfless impermanent limited and conditional names and forms undergoing and projecting different impermanent changes/conditions/states in NOW, where all kinds of names and forms ceaselessly arising, changing, decaying, disintegrating, and passing away, where all kinds of selfless elements that form all kinds of names and forms are undergoing the cycle of forming, changing, disintegrating, and transforming, governed by the nature's law of cause and effect, in NOW', it is not something that happens upon death beyond the momentary mortal selfless impermanent limited and conditional life existence and function of this body and mind, that is non-self, where many minds believe as upon the countless deaths of countless separate different life existences that belong to an eternal permanent independent infinite existence of an all time ancient immortal individual spirit/soul/consciousness (that doesn't exist) that resides momentarily in countless different separate life existences under particular name and form transitioning under different realms/worlds/spheres/realities.
All kinds of realms are manifesting, arising, changing, and passing away in the mind, in NOW. It is not something exists outside or beyond the mind. It is not something exists outside or beyond NOW. The different realms are merely the reflection of the impermanent states of mind. Ceaseless restless births and deaths (ceaseless countless thoughts after thoughts arising, changing, and passing away) forming or give rise to the different realms (different states of mind), where all THAT ceased existing or vanished upon the silence/stillness of the mind (Samadhi).
All are the creations of MAYA. All kinds of names and forms (thought current) are arising, changing, and passing away (ceaseless and countless births and deaths) in the mind. - The teachings of Yoga Vedanta
The belief of the existence of an eternal permanent independent infinite existence of an immortal individual pure and perfect spirit/soul/consciousness and the belief of the existence of a beginningless and endless reincarnations/rebirths (the endless loop of the infinite wheel of ceaseless births and deaths of countless different separate life existences that is beginningless and endless) transitioning in the different realms/worlds/spheres/realities, where the immortal individual pure spirit/soul/consciousness resides in the different countless selfless impermanent limited and conditional mortal physical structures of impure body and mind undergoing the countless reincarnations/rebirths under different separate momentary mortal life existences transitioning in different realms/worlds/spheres/realities based on the belief of good/bad/neutral karma that is inexhaustible, as every single thought/action/reaction/speech/desire will inevitably give rise to the boundless chain reaction of good/bad/neutral karma, are contradicting teachings/beliefs/values/practices that contradict one another.
Such ideas/values/beliefs are also being used as the reasonable justification to justify all kinds of physical/mental/emotional/financial/sexual abuse, exploitation, ill treatment, bullying, cruelty, suffering, illness, injury, damage, loss, unjust, discrimination, painful sorrow, and all kinds of physical/mental/emotional suffering inflicted by the ignorant minds unto oneself and the others, justifying that, "It is good for you to suffer all these. I am doing you a great favor by inflicting all kinds of painful suffering and difficulties unto you to help you to burn off your past accumulated bad karma. It is all good for you. Don't retaliate. Don't runaway. Don't complain. Don't tell anyone. Be good and thankful to me, and accept the painful suffering in silence, and all your bad karma will be burning off. The more you suffer the better it is."
If the mind truly immerses into meditation and self-inquiry to be inquiring towards the truth of everything diligently and determinedly, the mind will eventually realize and understand towards all kinds of 'defect'/'ignorance' that exist in the many existing teachings and practices of the contaminated/manipulated 'buddhism' under different names and forms, that is being contaminated by and not different from any other forms of worldly egoistic cultural, religious, spiritual, tribal, communal, or even commercial, or national, or political ideas, values, practices, aspirations, and visions.
Inquire the truth of everything, including all that is here, and be free.