The imparting of the Sign of Peace at Mass is not a mere gesture of good will from one person to another. No handshake, no nod of the head, no back slapping hug will suffice for this moment in the Sacred Liturgy. It is a profound receiving and sharing in the peace that comes only from Christ Himself. That is why the priest prays the following prayer first.
Lord Jesus Christ, who said to your Apostles: Peace I leave you, my peace I give you, look not on our sins, but on the faith of your Church, and graciously grant her peace and unity in accordance with your will. Who live and reign forever and ever. Amen.
It is clear that this peace comes from the Heart of the Savior—from a Heart that knew tremendous turmoil and sadness, and even desolation during His Passion. We need think only of Christ’s agony in the garden of Gethsemane, when He sweat blood because of the sorrow and pain He was experiencing (Lk 22:44). And, yet, from His Heart, he gives us His peace. He can do so, because in His humanity, He may undergo great distress, while in His divinity, He remains in loving communion with His Heavenly Father. In this profound unity of the Holy Trinity, Father, Son, and Holy Spirit, peace is found and is left to us by Our Lord precisely by the fearful Passion and Death that He underwent for our salvation.
In the above prayer, the priest asks Jesus not to look upon our sins, but on the faith of the Church. Even though the Church is the Mystical Body of Christ on earth, it is comprised of saints and sinners. Our Lord in His tremendous mercy looks upon the Church and sees the sins that are committed by its members, but He also beholds the saints and their lives of holiness lived out in faith. He sees those who struggle and fall, and then rise up again to pursue holiness through repentance. His Heart, from which flows forth great mercy, is also the source of unity and peace. Communion with Him, which is effected by the reception of His Body and Blood in the Holy Eucharist, makes unity in the Church possible and allows true peace to reign.
Recognizing this, we can then turn to one another and exchange the sign of peace, which originates only in the Heart of the Savior.
Most Reverend William J. Waltersheid Auxiliary Bishop of Pittsburgh