Catechism of the Catholic Church
608 After agreeing to baptize him along with the sinners, John the Baptist looked at Jesus and pointed him out as the "Lamb of God, who takes away the sin of the world". 422 By doing so, he reveals that Jesus is at the same time the suffering Servant who silently allows himself to be led to the slaughter and who bears the sin of the multitudes, and also the Paschal Lamb, the symbol of Israel's redemption at the first Passover. 423 Christ's whole life expresses his mission: "to serve, and to give his life as a ransom for many." 424
English Translation of the Cathechism of the Catholic Church for the United States of America © 1997, United States Catholic Conference, Inc.