Psalm 51[50] is one of seven Psalms known as the penitential psalms because they express in a striking manner the meaning and need for repentance. "My sacrifice, O Lord, is a contrite spirit". In these words the Psalmist summarizes a doctrine often preached by the great prophets, namely that the ritual and ceremonial aspects of our religion must be paralleled by a deep interior conversion as we keep turning to God in repentance: our heart must be humbled and contrite.

Humility is a virtue closely related to truth: we become truly humble, not by despising ourselves or "putting ourselves down" but by deepening our self-knowledge, our awareness of the ways in which we fail to live as the image of God and as true disciples of Jesus. This self-knowledge gives us the wisdom and the proper motivation to strive for holiness.

This self knowledge will also include an ever deeper realization that God has loved us from all eternity and is constant in his affection for us (Jer 31:3), constant to the point where he gave his only Son, and his Son Jesus offered the only sacrifice which is inexhaustibly the source of life and grace.