In the beginning was the Word, and the Word was with God, and the Word was God.
   John 1:1, King James Version. Project Gutenberg #10

The Cloud of Unknowing (anonymous, late 14th c.)

God known by love and not by thought. Quoted in restless.
sacred-texts.com, ch. 6

Julian of Norwich (c. 1343 – after 1416)

An anchoress who wrote Revelations of Divine Love, the earliest surviving writing in English known to be by a woman.
Wikipedia

Meister Eckhart (c. 1260 – c. 1328)

[paraphrase] He taught a letting go so complete that even our ideas of God have to go too, so that God can be found beyond them.
Wikipedia

Augustine, Confessions, trans. Pusey

The restless heart.
Project Gutenberg #3296