"The salient feature that is characteristic of enlightenment that’s independent of the tradition, whether it’s Christian, Buddhist, Moslem, Hindu, Sikh, Native, Atheist, etc.—the common denominator is that 'shift in perception of I-amness.' However, depending on a person’s background, and also how a person interprets the experience, the language that’s used to describe what is realized may be very different.
Buddhists formulate the shift in perception of I-amness as 'there truly is no self. Within a lot of Hinduism the very same experience is described as discovering the True Self in a way that implies it’s a thing – the Witness, the True Observer, Pure Consciousness, etc., etc. You might think just based on the language that the Buddhist formulation and what many of the Hindu’s talk about are unrelated or perhaps even opposite experiences.
It can get even more confusing when you read the classical texts in the original language they were written in. The Buddhists say enlightenment is to realize there is no Atma, which is interpreted as self-as-thing. Most Hindu teachers say enlightenment is to find the Atma, which is interpreted as the True Perceiver, or the Nature of consciousness that’s in some way behind all the appearances. So one says find the true Atma and the other says there truly is no Atma. You might think they’re talking about completely different experiences but as far as I can see they’re using different descriptions in talking about the same thing.
When you meet the Hindu babas and the Buddhists masters and you talk and interact with them, you get the same body language and you get the same vibe. It seems the same re-engineering of the human has taken place in both cases, but the language they use to describe this sounds antithetical.
The Christian mystics will often talk about the soul merging with God. Based on the words alone you might think that what they’re describing is quite different from the Hindu or Buddhist adepts. As far as I can see it’s part of the same re-engineering of the human. For example when St. Theresa of Avila talks about merging with God she says 'it’s like water and water.' But then she also says 'the self-forgetting is so profound it seems as though the soul no longer exists.' When a Roman Catholic in the sixteenth century says, 'when you merge with God it seems like your soul doesn’t exist anymore,' it is an extraordinary statement.
St. Theresa’s description of the contemplative path not only passed the test of orthodoxy, it has become orthodoxy! It is the standard map in the Roman Catholic tradition of the Christian meditative and contemplative path. So we can see that the Buddhist no-self model can be interpreted as akin to some of the things that St. Theresa says.
So a dramatic and permanent shift in the perception of identity is what to look for if you want to spot enlightenment across various spiritual traditions worldwide. Somehow it shakes the normal identity either in the sense of seeing there’s no thing called a self, or in the sense of identifying with a Pure Consciousness that is other than one’s mind and body, or in the sense of merging with one’s Source."
I tend to agree with Shinzen in that although mystics from different backgrounds speak in drastically different ways, they are undergoing the same type of spiritual transformation. In Shinzen's words, they give off "the same vibe."
For more from Shinzen Young, check out this post.