Twenty-five centuries ago the Buddha crossed almost the whole of India to preach the Way to Enlightenment, to Nirvana. According to the Buddhist teaching "That which we are", "That which perceives", is a composition of various processes (skanda), processes consisting of corresponding flows, successions, momentary states, phenomena (dharma). To reach Nirvana all these processes must be exhausted, overcome. There are various grades on this road. Beyond some simple rules that determine what we should not do and what we should do, the sensory activity (in general or by the use of some postures) should be overcome and then the mentality that connects us through the senses to the external world (ventana)... The four dhyanas are intended to eliminate the internal mentality (amjna , samskara , vijnana). The four samapatis manage the perception of existence in a purely metaphysical realm (vijnana, four categories). The Ultimate Reality leads us to a Consciousness without "consciousness", without "existence", without activities. The Enlightenment. Nirvana, is not a state of non-existence in the absolute sense but a State where any perception of relative existence is absent. What it really is has to be discovered by oneself, experiencing it.
Five centuries after the Buddha, Christ preached his own way to the Truth, in the wider region of Galilee and Judea. The "John" Gospel (regardless of who the real author is and whether the words he puts into Christ's mouth are Christ's or not) is the innermost of all sacred texts. Johannine theology handles metaphysical concepts and perceptions that clearly stem from an inner Hellenic conception of Reality but in a way that goes beyond a simple metaphysical view by promoting the experience of Christ as the Ultimate Reality. All Johannine Theology is condensed into one phrase that the author puts into the mouth of Christ "I and the father are one ". The two subjects are identified in "are". If the small human ego contains God, then God is "small". But if the Ego expanded and became as vast as the sky then the identification makes sense. However, Christ, the "I" is no longer an ordinary person. In reality God, Truth, son of God, son of man, I, man, All these are identical. Man, like the Model Christ, must rise, expand to the Infinite to contain God.
A few centuries after Christ and John, the Neptic fathers described in detail the way to Theosis (deification). Beyond some external rules we should overcome the sensory activity as well as the mentality that is directed towards the world and turn inward, towards the inner man. There are three stages in the overcoming of inner mentality, corresponding to the three varieties of thinking. In the next three stages the Consciousness, the mind, in the terminology of the Neptics, must be cleansed of all perception of personal existence and become shapeless, formless, monoid (or without species). The Final Attainment makes the mind immeasurable so that it can receive the Godhead and become deified (by grace the texts say, by nature we believe, but that doesn't matter).
In the last century the most important philosophical movement of the century, Existentialism, seeks Existence in terms similar to those of Buddhism and Christianity and with actions that do not differ from the analogous actions of the Buddhist meditator or the Christian neptic. In Heidegger's Philosophy Da-sein (here-being, present existence, present consciousness) is "That which we are", "That which perceives". This "Here-is" must be cleansed of all "here" to remain Pure Sein. All these determinations of Existence are external activities, mentalities, internal processes, even the very perception of existence, of relative existence.
THE ETERNAL TRUTH
In the end, it seems that the Truth is Eternal and is formulated again and again and everyone can search and formulate it in their own way. Human intelligence is built everywhere and always in the same way and always leads to the Truth Itself, to WHO YOU REALLY ARE, to DIVINITY. But all this will be widely understood, by the common man, in the next millennium.