The Catholic Church baptizes infants because that has been her consistent practice from the beginning.  Scripture nowhere commands us nor forbids us to baptize little children.  But the Book of Acts reports several occasions when the apostles baptized adults along with their entire households (Acts 16:15, 33 and Acts 18:8 — compare Acts 11:14).  St Paul also recalls baptizing an etire household in the city of Corinth (see 1 Cor 1:16).  In all likelihood, these families and their servants would have included small children, so they too would have received Baptism.

The clearest indicator that the Church has always baptized infants, however, is the witness of the early Church fathers who received their faith and practice from the hands of the apostles and their immediate successors.  St. Irenæus (c. 125-c. 203), for example, was a bishop trained by St. Polycarp, himself taught by St. John.  In his work Against Heresies, Irenæus wrote that Christ came to save those who are “born again in God” through Baptism, including “infants and children.”

The Church fathers were known for their vocal, stubborn opposition to any major innovations in Christian belief or practice.  So we can be sure that many of them would have vehemently protested in their teaching and writing if the Church had begun infant Baptism as a novelty in their day.  On the contrary, however, their testimony to this practice is universal.

Why would Christians baptize little children who have no clue what the sacrament is all about?  Because Baptism, as with all the sacraments, accomplishes real, objective spiritual work.  The effects of this particular sacrament are not dependent on the faith or understanding of a child being baptized.  We receive Baptism, Scripture tells us, “for the forgiveness … of sins” (Acts 2:38).  The Catholic Church teaches that Baptism washes away both original sin and actual sins from our souls, takes away the punishment for these sins, and infuses in us a number of divine graces.

If the sacrament accomplishes all this, why delay Baptism until a child can understand it?  Consider this parallel: Infants have no idea about what is accomplished by a bath.  Should parents wait to bathe their children’s bodies, then, until they are old enough to understand?  Of course not.  Now should they wait to have their children’s souls washed clean in Baptism.

Related Scripture:

Texts Cited:  Acts 2:38; 11:14; 16:15, 33; 18:8  •  1 Cor 1:16
General:  Mt 19:14  •  Mk 16:16  •  Jn 3:5  •  Acts 2:38; 22:16  •  Rom 2:28-29; 6:3-4  •  1 Cor 6:11
Catechism of the Catholic Church:  403  •  977-978  •  1213-1284  •  1290