Roman Catechism 16.97

Chapter 16 — Part II: The Sacraments — Baptism

Section 97. The remission of all sin, original and actual, is therefore the peculiar effect of Baptism. That this was the object of its institution by our Lord and Saviour is clearly stated by the Prince of the Apostles, to say nothing of other testimonies, when he says: Do penance and be baptised every one of you, in the name of Jesus Christ, for the remission of sins.