In thus allowing God to work in it, the soul … is at once illumined and transformed in God, and God communicates to it His supernatural Being, in such wise that it appears to be God Himself, and has all that God Himself has. And this union comes to pass when God grants the soul this supernatural favour, that all the things of God and the soul are one in participant transformation; and the soul seems to be God rather than a soul, and is indeed God by participation; although it is true that its natural being, though thus transformed, is as distinct from the Being of God as it was before…

(Saint John of the Cross)