Pedobaptism is the practice of baptizing infants or very young children, based on the belief that they are included in the covenant community because of their believing parents. In pedobaptist theology, baptism does not guarantee salvation but sets the child apart for future faith and discipleship within the church. Those who hold to pedobaptism—such as many in Reformed, Anglican, Lutheran, and some Methodist traditions—view it as visible a sign of inclusion in the church, similar to how circumcision marked inclusion in the Old Covenant community. However, unlike circumcision, baptism is given to both boys and girls. Likewise, baptism is not like circumcision because it follows personal faith and signifies inward regeneration and union with Christ, whereas circumcision was a physical sign given to male infants, regardless of their belief. The New Covenant emphasizes internal transformation, making baptism a response to salvation, rather than a prerequisite for covenant membership.
Is baptism an extension of circumcision, which indicated that someone belonged to the Old Testament community? A particular Reformed Protestant tradition, known as pedobaptism, sees a direct connection between the two signs. They argue that, just like circumcision was a sign that one was part of the Israelite community, baptism is a sign of belonging to the church community.
To this point, most would agree that there is at least a loose similarity between them. However, the pedobaptist view goes further. They argue that just like there were unbelieving Israelites who were circumcised because their parents were Israelites, so also should the children of believers be baptized. This is why they baptize newborns and why they are called pedobaptists, where “pedo” means “child” in Greek.
Note that while this practice is similar in form to Roman Catholicism’s baptism of infants, unlike Roman Catholicism, pedobaptists do not believe the infant is saved or has original sin removed because of the baptism. Rather, they view it merely as a sign that shows that the child has been given special, providential access to God’s grace by being able to participate in church life, because of his or her parents' belief, in a way that most unbelievers do not have access. In short, the baptized child will grow up surrounded by believers who regularly influence him or her toward Christ.
However, as already seen, the New Testament pattern is that people are saved and then baptized. This is why, in contrast to pedobaptists, many believers are called credobaptists, where “credo” is a Latin word for “I believe.” That is, they argue for believer’s baptism as the only time baptism is to be performed.
Perhaps the strongest New Testament verse a pedobaptist has to support his or her view of infant baptism is Acts 16:33. This is the account of a jailer who was saved after Paul and Silas did not attempt to escape after an earthquake (Acts 16:25–30). After being saved, we read, “[the jailer] took them the same hour of the night and washed their wounds; and he was baptized at once, he and all his family” (Acts 16:33). The argument is that “all his family” indicates that baptism was applied even to those who were unsaved but a part of the same household.
However, because Acts 16:33 is not a prescriptive passage (a passage explaining what to do), but rather descriptive (simply saying what happened), we need to be careful about not allowing this passage to override other clear, prescriptive passages. However, even considering the argument at face-value, there’s a weakness in it. Just prior to Acts 16:33, Paul said, “Believe in the Lord Jesus, and you will be saved, you and your household” (Acts 16:31). Surely Paul was not saying that if the jailer, alone, believed, his household would also be saved. That would be directly contrary to the rest of the New Testament, which says that we are each individually guilty and individually responsible. Instead, Paul was simply expressing the hope that the jailer’s household would also believe. It is even probable that the household was present, given that they were no longer inside the prison, but outside, perhaps in the courtyard, with others listening in on this conversation. In any case, just like Paul could not be saying that everyone in the household would be saved if the jailer believed, he did not mean that unbelievers in the household were to be baptized. He simply meant that those of the household who believed were also to be baptized.
Another minor problem with the pedobaptist view is that only males were circumcised, whereas both men and women are to be baptized. So, even conceptually, there’s a difference between these signs. They would argue that the New Testament expands the sign, but that is an argument based on the assumption that the two signs are the same.
Finally, in the Old Testament, circumcision was the means for entry into the covenant. Foreigners, for example, could not enter the community unless they were physically circumcised. Conversely, baptism comes after one has already entered the church through faith. Rather than how one enters, it is how one identifies with the community he or she just entered. This also indicates a discontinuity between the two signs.