“But the divine mystery is inherent in the divine, a part of the nature of God, and can never disappear. And this means that it is still a mystery even to the mystic who has directly experienced it, nay, even to God Himself. That is why it is ineffable. The mystery and the ineffability of God are one and the same thing.”

Source: The Last Song

Source: Creation Myths (1972), Deus Faber, p. 140 - 141

[2014, In the Face of the Absolute, World Wisdom, 99, 978-1-936597-41-3]
God, Outline

Source: The Sayings and Teachings of the Great Mystics of Islam (2004), p. 86

4:1
Church Dogmatics (1932–1968)

As translated in In Love with Eternity : Philosophical Essays and Fragments (2005) by Richard Schain, p. 47
Dream and Reality (1949)
Context: I see myself immersed in the depths of human existence and standing in the face of the ineffable mystery of the world and of all that is. And in that situation, I am made poignantly and burningly aware that the world cannot be self-sufficient, that there is hidden in some still greater depth a mysterious, transcendent meaning. This meaning is called God. Men have not been able to find a loftier name, although they have abused it to the extent of making it almost unutterable. God can be denied only on the surface; but he cannot be denied where human experience reaches down beneath the surface of flat, vapid, commonplace existence.

Source: The Outermost House

Source: Dictionary of Burning Words of Brilliant Writers (1895), P. 259.

"Anubis" to the Sphinx, in Act 2 of The Infernal Machine (1932); Collected Works Vol. 5 (1948)