The Baptism of Our Lord
On the surface, the Baptism of the Lord seems like an odd feast. The Church teaches that the sacrament of Baptism is necessary for the remission of sins, most particularly Original Sin. Yet, Jesus was born free from sin and lived His entire life without sinning. So, unlike the rest of humanity, Jesus had no need of Baptism. Why, then, was He baptized?
The fact that Jesus allowed John to baptize Him, even though He was sinless, reveals two things. First, it shows that Jesus takes our sins upon Himself. Second, it shows that Jesus understands His baptism as an anticipation of His Passion and Resurrection. (Taken from the Youth Catechism of the Catholic Church)
Click here to read what the Catechism of the Catholic Church teaches about the Baptism of Jesus.