Following the initial greeting at Mass, there is the Penitential Act. This can take three forms – and indeed a fourth. The first form is the traditional prayer for the acknowledgement of sin called the Confiteor. This Latin name is simply the first word of the prayer in Latin and so means the “I confess”. Its emphasis is upon the community’s acknowledgement of its sinfulness which is done before God and each other: “I confess to almighty God and to you, my brothers and sisters…”. It is concluded by the priest calling God’s mercy down on the whole community including himself.

The second form of the Penitential Rite is the very brief dialogue between the priest and the people:
“Have mercy on us, O Lord. Reply: For we have sinned against you.
Show us, O Lord, your mercy. Reply: And grant us your salvation.”

This is again concluded by the priest calling God’s mercy down upon all.

The third form of the rite consists of three phrases used before the invocation ‘Lord, have mercy’. These phrases can be chosen as is suitable for the liturgy of the day. There are sample phrases given in the Missal. And these three phrases are then followed as in the other forms by the priest calling upon God’s mercy.

If ‘Lord have mercy’ has been used as part of the Penitential Rite, it is not said or sung separately afterwards.
The use of the Penitential Rite is a new element introduced into the liturgy by the reforms following the Second Vatican Council. Its equivalent – for those who can remember – were the prayers at the foot of the altar in the pre-Vatican II liturgy.

By Frank O’Loughlin