If Mahayana Buddhism is against eating meat, why do some of the Tibetan practitioners eat meat? It is not because the scriptures gave them permission to do so but for other reasons. As you all know, most of the Tibetan Plateau is unsuitable for growing vegetables and rice. In the area where it is possible to grow crops, the yield is very low. And lacking sufficient transport facilities makes it difficult to have contact with the outside world. Especially in the pastoral areas, there is only tsampa (roasted ground barley) if people do not eat meat. In earlier times, due to the scarce availability of transportation, it was almost impossible for nomads to have contact with people outside of Tibet. Even within Tibet, people kept rather infrequent contact with one another. For example, some pastoral and agricultural areas in Qinghai were hundreds of miles apart. People there could only rely on horses and yaks to reach one another. The journey was treacherous and offered no guarantee of a safe return. Therefore, those in the pastoral areas had no choice but to eat meat because of the environment they were in. Although Mahayana teachings strictly prescribe vegetarianism and Tibetan practitioners also knew that eating meat is wrong and not in accord with the doctrine of Mahayana Buddhism, they still could not be vegetarian for the reasons described above. So they ended up eating meat, but only the three kinds of clean meat, never the unclean ones.

~Depicted from THE RIGHT VIEW - Why Vegetarian?

For example, some people believe that wearing designer clothes, driving an expensive car and living in a luxurious mansion symbolize their high social standing. However, this is in fact what the Buddha meant by self-indulgence because these objects are not necessities. People can never be fully satisfied with their lives if they do not know how to control their desires, as desires can grow and expand endlessly. No matter who you are, there will always be someone who is better than you. If your aim is to get to the top social stratum, your whole life will be spent in the pursuit of such vanity until the end. The consequence of chasing endless desires is never to be happy. Many such cases can be found in our daily life either from our own experience or that of other people. It is therefore important to be content with fewer desires in life.

~Depicted from THE RIGHT VIEW - A Buddhist’s Mode of Life

When rebirth is about to take place, the bardo being will encounter a man and a woman in sexual intercourse. If the being is to be reborn as a male, it will feel anger and jealousy toward the man but desire for the woman; if the being is to be born as a female, it will harbor anger and jealousy toward the woman but desire for the man. As long as desire and anger are both present, rebirth will take place immediately. The first few months after taking rebirth, one remains unconscious. Because this period of unconsciousness lasts a long time, one forgets everything that happened in the last life after being born.

~Depicted from THE HANDBOOK'S FOR LIFE JOURNEY - On Death And Rebirth-How to Take Rebirth

Without practice or mind training, we cannot be sure of attaining liberation. For instance, over the several decades in our lifetime, we do not in general have to worry about our livelihood; as long as we are willing to work, it is more or less guaranteed. However, death, this uninvited guest, comes when we least expect it. At the critical moment, we are not at all prepared to confront death or transform it into the path. Invariably, we are helpless when death arrives, so the question of birth, aging, illness, and death is a more important one than existence. If we cannot address this problem properly, it is more frightening than the struggle to stay alive; if we can come to terms with the problem in the correct way, it will be more meaningful than solving our livelihood. Therefore, practice is extremely important.

~Depicted from THE FOUR SEALS OF DHARMA - The Importance of Practice

To know death correctly can help us overcome fear, anxiety and evasion when death is mentioned because we already know that death is only a part of the cyclic process of life, not the end. There is no need to feel disheartened and pessimistic when facing death. On the contrary, we may even be able to elevate our life to a different level when in death if we know how to make use of the opportunity.

~Depicted from THE HANDBOOK'S FOR LIFE JOURNEY - On Death And Rebirth-How to Face Death

After a person has killed a being or stolen things, the karmic seed of such action will remain in this person’s alaya consciousness. When it will germinate is uncertain, however. The scriptures often used the analogy of harvesting crops to illustrate the timing of karmic effect. There are great varieties of grains and vegetables and the length of time for them to ripen varies. Some may ripen in only one to two months, others five or six months, or even longer. The types of seeds, the geographical location and the climate are all contributing factors to this disparity.

~Depicted from THE RIGHT VIEW - On Cause and Effect

Assuming mankind truly believed in cause and effect, there would be no killing, lying, and stealing; no contamination of oil, meat, milk powder, and other food products; no violence and war. People would interact with complete sincerity.

Therefore, the Buddhist teachings on cause and effect are of immeasurable benefit to modern society.

~Depicted from ARE YOU READY FOR HAPPINESS  -  Spiritual Equipment for Modern Times

About the powers of the four different types of karma, only the omniscient Buddha knows. Ordinary people or non-Buddhist practitioners possessing some psychic powers and even arhats would not know their intricate workings thoroughly. During the time of the Buddha, there were many non-Buddhist practitioners in India who, with their clairvoyance, saw lifelong virtuous people find rebirth in the hell, hungry ghost, or animal realm instead. They questioned, “If cause and effect was truly infallible, why would virtuous people not end up well?” Hence, they viewed the idea of cause and effect as pure nonsense.

~Depicted from THE RIGHT VIEW - On Cause and Effect

The generation stage of Vajrayana is a specific practice for the training of pure perception. Via the generation stage, even ordinary beings don’t have to wait too long to achieve accomplishment. Upon reaching the highest state, one sees everything around as nothing but manifestations of the buddha; nothing is defiled. This is where even ordinary beings who have not attained the first bhumi of the bodhisattva path can successfully reach. So, in terms of purification of phenomena, tantra has swift methods of its own.

~Depicted from GATEWAY TO VAJRAYANA PATH - Sutra and Tantra: Similarities and Differences--based on the view of Rongzom Pandita