During the Last Supper, Jesus makes this pledge to His apostles:

“Peace I leave with you; my peace I give to you. Not as the world gives do I give to you” (John 14:27).

After His resurrection, the glorified Lord Jesus appears to the apostles extending His promise of peace:

Jesus came and stood among them and said to them, “Peace be with you.” … Jesus said to them again, “Peace be with you” (John 20:19, 21).

The Church mercifully and joyfully extends Jesus’ promise of peace during every Mass. Just prior to Holy Communion the priest, acting in the person of Jesus, offers Jesus’ peace to the people who, in turn, share it with each other.  Jesus’ peace stirs our souls to avoid everything that threatens unity and connection.

Thus, Jesus’ peace is necessary if we are to receive the Eucharist worthily.