In Mahayana Buddhism there are many Buddhas and they are seen as cosmic beings that may choose to appear in human form to teach others. Although they believe that shakyamuni Buddha did follow the Bodhisattva path to achieve Buddhahood he had in fact been enlightened for eons and his appearance is one of several. He did not in fact die but rather he chose to appear to so that he may help us learn his teachings as they will not become too reliant on him and it will encourage them to seek their own path. This belief has been formulated into three separate bodies which make up the Trikaya doctrine. These bodies are: Nirmanakaya, Sambhogakaya, and dharmakaya.
Nirmanakaya is described as the transformation body; this is the earthly manifestation of the Buddha that he uses so that he can teach us more easily. Buddhas can create any form that they want to, and even have the ability to be several different forms at once if they so wish. Some see these as only being a sort of manifestation of the Buddha but others see them as genuine “flesh and blood” beings. This has obvious parallels to be drawn with Jesus Christ as he is the bodily incarnation of God in Christian beliefs, the idea that God had to make himself man to help teach us is closely related to the fact that Buddhas must make themselves men to help teach us as well.
Sambhogakaya is sort of a bodily form that Buddhas and other advanced bodhisattvas take; they can become accessible to bodhisattvas and those who are in the heavenly realms. They can appear in visions during meditation practices and offer teaching to those who are less enlightened than themselves. They have the ability to create “pure lands” where through the power of their own enlightened minds they can create a world which is helpful for those who are trying to attain nibbana. In these lands it is easier to understand and practice the Dharma. Other Buddhas create “Buddha fields” within non pure lands such as the one that Siddhartha created in our own impure world. This form of the Buddha is often seen as the equivalent to God the Father in Christian beliefs as he exists in a world separate from
our own but is nevertheless reachable through following his teachings.
Dharmakaya is the Dharma body and is, in some ways, beyond description as it can be seen as synonymous to enlightenment; it is the realisation of the truth of all things and the freedom from all suffering. There is no duality within the dharma body meaning that one can see beyond the simple idea of you and me and sees the greater picture that the universe is in fact all made up of the same “stuff”. If we were to take an electron microscope and look at the individual subatomic particles that make up my own hair and compare those to the individual subatomic particles in a rock they would be pretty much indistinguishable and hence we are at our most basic level all the same.
It is therefore seen as in many ways identical to the tathagagarabha within all beings. The tathagagrabha is the “Buddha embryo” that exists within everything; it is understood as the bit of Buddha in all of us that needs to be developed for nibbana to be achieved. It is also seen by some as an existing Buddha nature within us that will be released when external things that cloud the mind are removed. There is often a parallel between Dharmakaya and the Holy Spirit as exists in everything and holds within it the ultimate truth if we are willing to do what is required of us to achieve enlightenment.
Due to this doctrine many view Mahayana Buddhism as a God amongst men rather than, as Theravada Buddhism which suggests that the Buddha is neither a god nor a man but an awakened being who understands that there can be no distinguishing between the two, everything is ultimately made up of the same things.