But just as Buddhism is all about being present in the moment, nirvana is also in the here and now. It is, actually, nothing more than a state of mind. Let me quote from several Buddhist sources.
First, a verse from the Heart Sutra:
“Bodhisatvas, abiding always in perfected wisdom,
Their minds have no fears or obstructions,
Therefore they have no fears or obstructions;
Free of confused illusions,
They reach nirvana.”
The "only" door that needs to be opened to reach nirvana is to have no fears or obstructions, to be free of confused illusions. And one achieves that by abiding in perfected wisdom, which is principally to be aware of the emptiness of all five skandhas ... appearance of form, feelings, perceptions, mental formations, and consciousness-ego, and experiencing things directly without the intervention of those ego-driven thoughts.
Next, two verses from an ancient Chinese poem, “Affirming Faith in Mind.”
“Do not reject the sense domain.
For as it is, whole and complete,
this sense world is enlightenment.”
“Not only here, not only there,
truth’s right before your very eyes.”
The point being made here is that when you see the sense world “whole and complete,” meaning as it truly is, with dispassion, free of the intervention of your thinking mind, free of labels, because you are aware of the emptiness of all five skandhas, that is enlightenment. Nirvana is being able to see things as they really are.
Finally, verses from a poem by the 18th century Japanese Zen master Hakuin, “In Praise of Zazen.”
“The cause of our sorrow is ego delusion.
From dark path to dark path
we’ve wandered in darkness-
... The gateway to freedom is zazen samadhi-”
“What is there outside us,
what is there we lack?
Nirvana is openly shown to our eyes.
This earth where we stand
is the pure lotus land,
and this body the very body of Buddha.”
The point here needs no further explication. Nirvana is right here, right now, if we are only able to see things clearly, just as they are, free of the intervention of our ego thinking-mind, free of labels.
In all three poems, nirvana is clearly in the here and now, with the pre-condition to experiencing it being an awareness of the emptiness of all five skandhas and being free of the intervention of our ego thinking-mind. (As noted in many of my posts, we can never be free of our ego or its thinking-mind; it is a part of us. But with awareness, we can be free of it’s intervention; when it arises we can choose not to engage it but just watch it subside.)
This is by no means easy to achieve - an understatement if ever there was one - but it is something which is possible and indeed only possible in the here and now. Remember that this is not a flash of light thing for most of us. It is an incremental process as we walk the path, with our slowly gaining more moments in more days in which we are aware of the emptiness of all five skandhas and experience things directly as they really are, with dispassion, free of all obstructions ... all labels, all fear and anxiety, doubt and confusion, anger, negativity, and lust. Thus we experience nirvana bit by bit, and for this we are grateful.