Now understand the deepest essence of your soul, I remained in a state of oneness with my Beloved, so that I melted into him and ceased to be myself what 'soul' is. Soul is a being that can be beheld by God and by which, again, God can be beheld. Soul is also a being that wishes to content God … The soul is a bottomless abyss in which God suffices to himself; And I was transformed and absorbed in the spirit and his own self-sufficiency ever finds fruition to the full in this soul, as the soul, for its part, ever does in him. Soul is a way for the passage of God from his depths to his liberty; and God is a way for the passage of the soul into its liberty, that is, into his inmost depths, which cannot be touched except by the soul's abyss.

Letter XVIII.