Maha Yoga
Lama Tharchin Rinpoche

Mahayoga emphasizes the creative phase of meditation; Anuyoga, the perfection phase with characteristics; and Atiyoga, the perfection phase without characteristics. The creative phase Mahayoga is based on the principle of purification. Purification does not mean that the universe and all beings are impure and must be purified. It means that the inherent purity of the universe and all beings must be revealed or actualized. The Mahayoga way of accomplishing this is through the four aspects of purification:
1) The basis of purification is the fundamental ground of pure buddha essence.
2) The defilements to be purified are the temporary dualistic appearances.
3) The method that purifies is the creation and perfection phases of meditation that transform impure perception into pure vision.
4) The result of purification is the attainment of the two kayas.
Practicing the method that purifies is easy, but it seem difficult at first because we are so entrenched in the impure perception that we are not aware of how we create it. If we can just realize that phenomena appear yet are not truly exist because they are inseparable from great emptiness we will destroy our impure dualistic perception. In Mahayoga we come to this important realization by creating the appearance of a wisdom deity through visualization, mantra, and concentration. When we "create" the deity in this way, we know that it is non-substantial and non-existent, yet we cannot deny our experience of it. Then by extension, we realize that this is also true of all phenomena. We see the " magic" of form and emptiness and realize the truth of pure vision. This is a great relief because it means that our defilements are not truly existent. For example, if we have a million dollars that we believe to be real, then we have a million dollars to take care of, so to speak. That is not easy. On the other hand, if we know that the million dollars is really just a concept and that it is inseparable from emptiness, our relationship with the million dollars will be free of attachment and grasping. What I am trying to point out is that appearances and emptiness are not separate realities, but a singe indivisible sphere of truth. Maybe it's hard right now to believe that the Mahayoga method of purification through deity practice actually works, or maybe it seems difficult to do because of there are deities to be visualized and so forth. Or maybe you think that deity yoga increases concepts instead of eliminating them.
The point to remember is that although we are temporarily deluded, we are not fundamentally different from Kuntuzangpo, the primordial buddha. Just to know this is inspiring and gives us confidence. The only way in which we do differ is in relation to the realization of the true nature of phenomena. Whereas Kuntuzangpo recognizes phenomena as the expression of his own nature, we do not. In the absence of surecognition, we externalize phenomena and experience the world and the beings that live in it as substantially real. This is the result of ignorance and delusion. Nevertheless, the fundamental nature is not contaminated or changed by our delusion because it is beyond cause and result, and circumstances.
Under the heading of the method of purification, I have just spoken about the pure perception of buddhas and the impure perception of deluded beings. But there is also a third mode of perception - the meditator's perception that is gradually shifting from impure to pure. In the beginning, the meditator must make a conscious effort to generate an experience of purity. But then as the meditator's skill improves and he or she relaxes, the experience of purity occurs naturally and deepens effortlessly. When the meditator and the meditator's experience are one and the same, then all appearances are realized to be pure.
If we try to understand the external physical world, we probably would talk about atoms and quantum particles. But the truth is that the origin of the universe is not found in atoms and particles. To find the true answer, we must acquire inner knowledge. The external world and the six realms of beings - "the problem" -- are created each moment of our existence through ignorance and our dualistic belief system. However, the solution (wisdom deity and pureland) arises in exactly the same way that the problem (the universe all beings) arises. It's just that the starting points are different - ignorance or recognition. So, what I am saying is that we are already capable of realizing nonduality. What we must to do is to find the right starting point.
This is a story I like to tell about the power of creating realities. Once upon a time, when Buddha was teaching his disciples that the outer world is all a matter of perception or in other words, that it's all in our mind, one disciple said: "Are you kidding? You mean there's no ocean and no world? Nothing exists except for conception?" In response, the Buddha told the story of a woman who once lived in Varanasi, a famous Indian city. At that time, thieves and bandits were in the habit of raiding the town and harming the residents. Everyone was terrified and panicked. The king tried to protect them but he was not successful. One lady took the matter into her own hands and defended herself my meditating that she was a tiger. She meditated so strongly that her neighbors began to see her as a tiger and so did the bandits. That took care of her problem!
This story also reminds me of when I first learned how to play cards. I was very excited about it and concentrated as hard as I could. When I went to sleep that night, all I could see before my eyes were the numbers on the cards flashing by. They wouldn't stop. Meditation is like that too. When you focus on a wisdom deity, all phenomena are seen through the lens of pure vision. Even if you dream of something scary, you immediately recognize it as natural manifestation and you are not afraid. This just happens naturally because you are grounded in pure vision. This also reminds me of what Dudjom Rinpoche once said: "In the beginning, the meditator chases after meditation, but later, meditation chases the meditator." I like that.