The Church from the beginning has practiced the Baptism of children. The reasons are very clear in Scriptures.
(Joh 3:5 DRB) Jesus answered: Amen, amen, I say to thee, unless a man be born again of water and the Holy Ghost, he cannot enter into the kingdom of God.
To the first Christians that baptized their children it was understood by them that Baptism is the doorway to salvation. St. Peter said the following:
(1Pe 3:18 DRB) Because Christ also died once for our sins, the just for the unjust: that he might offer us to God, being put to death indeed in the flesh, but enlivened in the spirit,
(1Pe 3:19 DRB) In which also coming he preached to those spirits that were in prison:
(1Pe 3:20 DRB) Which had been some time incredulous, when they waited for the patience of God in the days of Noe, when the ark was a building: wherein a few, that is, eight souls, were saved by water.
(1Pe 3:21 DRB) Whereunto baptism, being of the like form, now saveth you also: not the putting away of the filth of the flesh, but, the examination of a good conscience towards God by the resurrection of Jesus Christ.
The effects of Baptism are the regeneration of the soul (born again), eradication of original sin and actual sin and its effects on the soul. A baby does not have actual sin but does have original sin. Through Baptism we become members of the Body of Christ, of which St. Paul says the following:
(2Co 5:17 DRB) If then any be in Christ a new creature, the old things are passed away. Behold all things are made new.
(1Co 3:16 DRB) Know you not that you are the temple of God and that the Spirit of God dwelleth in you?
Baptism is the sacramental doorway into the Church:
(Mat 28:19 DRB) Going therefore, teach ye all nations: baptizing them in the name of the Father and of the Son and of the Holy Ghost.
The Bible teaches that everyone should be Baptized:
(Act 2:38 DRB) But Peter said to them: Do penance: and be baptized every one of you in the name of Jesus Christ, for the remission of your sins. And you shall receive the gift of the Holy Ghost.
(Act 2:39 DRB) For the promise is to you and to your children and to all that are far off, whomsoever the Lord our God shall call.
(Act 2:40 DRB) And with very many other words did he testify and exhort them, saying: Save yourselves from this perverse generation.
(Act 2:41 DRB) They therefore that received his word were baptized: and there were added in that day about three thousand souls.
(Act 2:42 DRB) And they were persevering in the doctrine of the apostles and in the communication of the breaking of bread and in prayers.
St. Peter at Pentecost said to the adults to repent but did not exclude children from Baptism, instead saying that everyone should receive the Holy Spirit not just those of age to repent. He said it is “to you and to your children”. That is why people in the early Church brought even their smallest children to be baptized as do parents today.
There is no necessity to repent for children to be Baptized according to Scriptures. The command to repent is not binding on infants nor to mentally incapacitated people as the intent of repentance is not to exclude those incapable of such an act. They are not to be condemned because of their lack of ability to repent. Certainly the same understanding should apply as we understand St. Paul’s statement in 2 Thessalonians 3:10 where St. Paul says that someone who does not work does not eat. Are we to deny children or the mentally handicapped sustenance? Certainly they should not, nor should they be denied eternal life.
The Old Testament required circumcision at eight days old as a sign of the covenant of God. The child had no knowledge of why he was being circumcised yet the parents brought the son to the synagogue to have this done. God accepted the child into the covenant for what the parents had done just as He accepts the Baptism when the parents present their child to be baptized. The Scriptures tell us clearly that Baptism replaced circumcision:
(Col 2:11 DRB) In whom also you are circumcised with circumcision not made by hand in despoiling of the body of the flesh: but in the circumcision of Christ.
(Col 2:12 DRB) Buried with him in baptism: in whom also you are risen again by the faith of the operation of God who hath raised him up from the dead.
We must remember what Christ said when there were those who attempted to forbid the children from coming to Him:
(Luk 18:15 DRB) And they brought unto him also infants, that he might touch them. Which when the disciples saw, they rebuked them.
Luk 18:16 DRB) But Jesus, calling them together, said: Suffer children to come to me and forbid them not: for of such is the kingdom of God.
(Luk 18:17 DRB) Amen, I say to you: Whosoever shall not receive the kingdom of God as a child shall not enter into it.
Can there be any doubt by a proper understanding of Scripture that children should be baptized? Certainly a complete understanding of the Scriptural verses shows clearly that children have the same need for Baptism as adults and that they should not be held away from this act by their parents or the Church lest they put the child in grave danger and the parents and/or Church are disobedient to the spirit of the teaching of Jesus and the apostles.