No purchase on borderless infinity

Nicholas [of Cusa] is thoroughgoing: we are ignorant concerning God and the world and Christ. His starting point is reminiscent of Gregory of Nyssa: we are to explore the implications of divine infinity. Knowledge requires boundaries to things that are to be named and measured, whose relations and distinctions it explores. Knowledge simply has no purchase on borderless infinity. 

JP Williams, Seeking the God Beyond: A Beginner’s Guide to Christian Apophatic Spirituality, p.103

Prayer - at least, contemplative prayer - is to put ourselves, as comprehensively as we are able, beyond boundaries. We are finite, bounded creatures; yet we are curiously able to reach beyond ourselves, not by knowledge or will, but by yearning, by love. 

John Keats once wrote, in a letter to his brothers,

I had not a dispute but a disquisition with Dilke, upon various subjects; several things dove-tailed in my mind, and at once it struck me what quality went to form a Man of Achievement, especially in Literature, and which Shakespeare possessed so enormously—I mean Negative Capability, that is, when a man is capable of being in uncertainties, mysteries, doubts, without any irritable reaching after fact and reason—Coleridge, for instance, would let go by a fine isolated verisimilitude caught from the Penetralium of mystery, from being incapable of remaining content with half-knowledge. This pursued through volumes would perhaps take us no further than this, that with a great poet the sense of Beauty overcomes every other consideration, or rather obliterates all consideration.

The Complete Works of John Keats: Poems, Plays & Personal Letters, p.763

For Keats, "the sense of Beauty" seems to have given him the beginnings of a "purchase on borderless infinity" - at any rate, he has learned the limitations of knowledge, and of the wonderfully expressed "irritable reaching after fact and reason". 

"All our steps are ordered by the LORD; how then can we understand our own ways?" (Proverbs 20:23 NRSV) Our unknowing extends even to our own actions and intentions. There is not only nothing we can think of God: there is nothing we can do to search him out. All we can do is sit still, and call this stillness prayer.

The author of The Cloud of Unknowing (Ch.6) wrote, "God can be loved, but not thought. By love, God can be embraced and held, but not by thinking..." And this is the point of our prayer: to remain still, in silence, allows the heart to find the empty places that open up within itself. Only when we cease trying to think of God can God be found. In the self-repeating words of the Jesus Prayer, or in the wordlessness of centering prayer, the irritable scratching of the mind after form and definition fails, and love floods in.