From Five Hundred Chapters by St. Maximus the Confessor, abbot.
"The Word of God, born once in the flesh . . . is always willing to be born spiritually in all who desire him. In them he is born as an infant as he fashions himself in them by means of their virtues. He reveals himself to the extent that he knows someone is capable of receiving him. He diminishes the revelation of his glory not out of selfishness but because he recognizes the capacity and resources of those who desire to see him. Yet, in the transcendence of mystery, he always remains invisible to all."
(Advent, Office of the Readings, pg. 519)