Catechism of the Catholic Church

The New Testament contains scarcely any prayers of lamentation, so frequent in the Old Testament. In the risen Christ the Church's petition is buoyed by hope, even if we still wait in a state of expectation and must be converted anew every day. Christian petition, what St. Paul calls "groaning," arises from another depth, that of creation "in labor pains" and that of ourselves "as we wait for the redemption of our bodies. For in this hope we were saved." In the end, however, "with sighs too deep for words" the Holy Spirit "helps us in our weakness; for we do not know how to pray as we ought, but the Spirit himself intercedes for us with sighs too deep for words." (2090)