He who asks to receive his daily bread does not automatically receive it in its fullness as it is in itself: he receives it according to his own capacity as recipient. The Bread of Life (cf. Jn. 6:35) gives Himself in His love to all who ask, but not in the same way to all; for He gives Himself more fully to those who have performed great acts of righteousness, and in smaller measure to those who have not achieved so much. He gives Himself to each person according to that person's spiritual ability to receive Him.
Maximus the Confessor