Although from the first Baptism was the universal means of entry into the Christian community, the NT contains no specific authority for its administration to infants. Since at least the 3rd cent., however, children born to Christian parents have been baptized in infancy. In the 16th cent. the practice (‘paedobaptism’) was rejected by the Anabaptists, and since the 17th cent. also by the Baptists (and later by the Disciples of Christ).
In the NT the children of Christians are regarded as themselves Christian, and where the Baptism of households is mentioned, children may have been baptized along with adults. The Apostolic Tradition explicitly states that little children are to be baptized first, and if they cannot answer for themselves a member of the family is to do so on their behalf. Origen refers to the Baptism of infants as an established practice, and Tertullian argued against it (witnessing to its existence). Even in the 4th cent. not all children of Christian parents were baptized in infancy (St Basil and St Gregory of Nazianzus were baptized in their twenties) but about this time the Baptism of children became increasingly normal. With the toleration of Christianity under Constantine, Baptism no longer entailed risks of persecution, and as the Church became identified with the State in the 5th cent., Baptism came to be regarded as a rite of passage connected with birth.
According to Catholic theology the Baptism of infants conveys the essential gift of regeneration. Those who reject the practice do so on the grounds that it lacks NT warrant and that as a mere ceremony (not a sacrament) it can convey no benefit to its unconscious recipient. In modern times there has also been some reconsideration of the traditional practice in view of the fact that many who bring their children to be baptized are themselves only nominally Christian, and the 1969 RC Order for the Baptism of Infants acknowledges that in some cases Baptism should be delayed. See also Baptism.