Catechism of the Catholic Church

The Psalter's many forms of prayer take shape both in the liturgy of the Temple and in the human heart. Whether hymns or prayers of lamentation or thanksgiving, whether individual or communal, whether royal chants, songs of pilgrimage or wisdom-meditations, the Psalms are a mirror of God's marvelous deeds in the history of his people, as well as reflections of the human experiences of the Psalmist. Though a given psalm may reflect an event of the past, it still possesses such direct simplicity that it can be prayed in truth by men of all times and conditions.