Above all else, we must seek faith, of which we read: purifying their hearts by faith. Blessed are the pure of heart, for they shall see God. Entrust yourself, therefore, to God. Commit yourself to him. Cast your thought on him and he shall sustain you so that you may say with confidence and faith that the Lord takes thought for me.
Persons who love themselves do not appreciate this–people who pretend to knowledge, who are absorbed in their own affairs, who take good care of the flesh in its desires and are deaf to the voice that says, Cast all your care upon him, because he cares for you.
Now to trust oneself is not faith but faithlessness. To place confidence in oneself is not trust but mistrust. The genuinely faithful are those who do not trust in themselves or hope in themselves; they become to themselves like broken vessels and so lose their lives as to preserve them for eternal life. Yet only humility of heart prevents the faithful soul from leaning on itself for support. Forsaking themselves, they come up out of the desert, leaning on their beloved, and thereby overflowing with delights.
from Sermon Five On the Eve of the Lord’s Birth, By St. Bernard of Clairvaux, Sermons for Advent and Christmas (CF 31, pp84-85)