The practice of infant baptism since the time of the early church was part of Augustine’s argument for original sin: it was clear that infants did not sin; they have inherited sin, otherwise baptism would be irrelevant.
Baptism is a sacrament, which Augustine defined as ‘an outward and visible sign of an inward and invisible grace.’ Baptismal water is used by God to save.
Baptism therefore saves a baby from damnation (John 3:5) but there is, of course, still the need to grow in the Christian life.
Augustine said that infant baptism is like the removal of a disease; one is left in a weakened condition; this weakness is remedied by Christian growth and other sacraments.
Huldrych Zwingli (15th-16th c CE) was a Swiss reformer who believed that the Bible is the sole source of truth.
Zwingli believed that the practice of infant baptism goes back to the Early Church (Acts 16:15;33).
Zwingli rejected sacramental views: God alone saves, with or without water.
Zwingli supported infant baptism on the grounds that it replaced circumcision as a sign of the covenant (Colossians 2:11-12), Christ welcomed children (Matthew 9:13-14), and that it is an occasion for parents to make pledges.
20th century theologian Karl Barth supported ‘believer’s baptism’: baptism only following a profession of faith – usually by full immersion (Acts 8:35-36).
All of the baptisms described in the New Testament occur after a profession of faith.
At the time of the reformation, those who practised believer’s baptism were called ‘Anabaptists’ (lit. ‘baptise again’).
Rebaptism was condemned at the Council of Trent in 1547.
As Anabaptists viewed infant baptism as unscriptural, they did not see themselves as baptising ‘again’.
Barth stressed that it is the person of Jesus is the sacrament of God (the outward sign of an inward and invisible grace) – not any ritual of the church.
Barth criticised the Church for always wanting to attain to more power than it has, for trying to mediate God’s grace.
Baptism for Barth is symbolic representation of salvation having already taken place in a believer’s life. It is a human response to God.
Churches which practice believer’s baptism today usually require a profession of faith prior to the act.
Churches that practice infant baptism require promises from parents and others to raise the child in the faith until they ‘confirm’ their faith as adults.