While most view the Reformation in terms of the Protestant break from the Roman Catholic church, the magisterial reformers were also forced to contend with the emergence of the Radical Reformation, which they believed to be equally in error. One of the key points of contention was the doctrine of baptism, with Anabaptist groups arguing that infant baptism was invalid, and those wanting to enter their communities needed to be (re)baptized. The magisterial reformers rejected this contention. Here Girolamo Zanchi (1516-1590), an Italian Reformed theologian and pastor who taught at Strasbourg, Heidelberg, and Neustadt, gives a concise presentation of one of the central arguments presented by mainstream reformers: as circumcision happens only once, and Christ died only once, then so too should baptism happen only once.

Circumcision, Baptism, and Christ’s Death All Happen Only Once

We believe that as circumcision was done only once in the flesh, so the baptism of water, which succeeded circumcision,For Christ also once died and was buried, and we are baptized into his death and are buried with him by baptism. being once rightly and lawfully received, ought not again to be repeated. We say that it is rightly and lawfully administered, when first the doctrine of the gospel concerning the true God, Christ and his office goes before according to Christ’s institution, and then the parties are baptized with water, and that of a lawful minister in the name of the Father, the Son and the Holy Spirit. For Christ also once died and was buried, and we are baptized into his death and are buried with him by baptism. Neither do we read the apostles ever did rebaptize any, except those which Paul did baptize, who had not been rightly baptized.

On Baptism, citing Colossians 2:11-12.

Graham Tomlin, ed. Philippians, Colossians. Reformation Commentary on Scripture, NT Vol. XI, p. 188.