also has a great weight of witness; for it was the infant age that first
merited to pour out its blood for Christ.
Catechism of the Council of Trent (1566)
Pt. II, Ch. II: If, then, through the transgression of Adam, children can
inherit original sin, with still stronger reason can they attain through Christ
our Lord grace and justice that they may reign in life. This, however,
cannot be effected otherwise than by Baptism.
Pastors, therefore, should inculcate the absolute necessity of administering
Baptism to infants, and gradually forming their tender minds to piety by
education in the Christian religion. For according to these admirable words
of the wise man: A young man according to his way, even when he is old,
he will not depart from it.
Catechism of the Catholic Church (1992)
No. 1250:
Born with a fallen human nature and tainted by original
sin, children also have need of the new birth in Baptism to be freed from
the power of darkness and brought into the realm of the freedom of the
children of God, to which all men are called. The sheer gratuitousness of
the grace of salvation is particularly manifest in infant Baptism. The
Church and the parents would deny a child the priceless grace of becoming
a child of God were they not to confer Baptism shortly after birth.
No. 1251:
Christian parents will recognize that this practice also
accords with their role as nurturers of the life that God has entrusted to
them.
No. 1252:
The practice of infant Baptism is an immemorial tradition
of the Church. There is explicit testimony to this practice from the second
century on, and it is quite possible that, from the beginning of the apostolic
preaching, when whole households received baptism, infants may also
have been baptized.