There are Christian groups, referred to as Paedobaptists, who believe that it is correct and even needful to offer baptism to infants and toddlers of Christian parents. Their argument for doing such is straightforward. First, there exists exact continuity between the people of God in the Old Testament and the people of God in the New Testament. Circumcision was the rite of initiation into the community that was covenanted with God in the Old Testament. In the Old Testament entrance into the covenant community took place as an infant and was accomplished through the act of circumcision. In the New Testament the rite of initiation into the covenant community is baptism. Therefore, baptism and circumcision parallel each other and therefore baptism should be offered to infants of Christian parents. This is born out by the fact that whole households were baptized in the book of Acts (16:15, 33; cf. 1 Cor. 1:16).
Although this set of arguments is quite logical, it is also quite unbiblical. First, although there is continuity between the peoples of God in the Old and New Testaments, there is also difference. Romans 9-11 clearly and distinctively indicates that God’s program with Israel has not yet been completed and that there is yet a future work to be done with them different from the work that is now taking place through the church. This is why Paul says, “25 For I do not want you, brethren, to be uninformed of this mystery, lest you be wise in your own estimation, that a partial hardening has happened to Israel until the fulness of the Gentiles has come in; 26 and thus all Israel will be saved; just as it is written, ‘The Deliverer will come from Zion, He will remove ungodliness from Jacob. 27 And this is My covenant with them, When I take away their sins’” (11:25-27). So continuity does not mean lack of differences.
Next, circumcision was the rite of entrance into the covenant community not just of infants, but even of adults. If one is going to argue that infants should be baptized, since infants were circumcised in the Old Testament, thus admitting them into the covenant community, then one must also allow for the same process in reference to adults as well. This, however, is clearly opposed to divine revelation. Notice God told Abraham in Genesis 17, when He first instituted circumcision as the sign of the covenant, that he was to circumcise all the males in his household (17:9-14). What did Abraham do in obedience to God’s command, “22 And when He finished talking with him, God went up from Abraham. 23 Then Abraham took Ishmael his son, and all the servants who were born in his house and all who were bought with his money, every male among the men of Abraham’s household, and circumcised the flesh of their foreskin in the very same day, as God had said to him” (Gen. 17:22-23). The inclusion of adults in the rite of circumcision contracting them into the covenant community was repeated in the Law itself (cf. Ex. 12:43-51). Obviously, there is an inconsistency here in their position. If allowing adults baptism is wrong, allowing infants baptism is also wrong.
What is the point? It is a failure of consistency both logically and biblically to allow infants who would not be converted to be baptized based on infants being circumcised in the Old Testament and then to not allow unconverted adults attached to covenant families to do the same. There is tremendous inconsistency at this point. If one is going to allow infants to be baptized, they must also allow unconverted adults to be baptized as well, which is patently unbiblical
Further, water baptism is not the New Testament equivalent of Old Testament circumcision. This is were the most glaring biblical mistake is made in this particular position. That which corresponds to the circumcision of the Old Testament is not baptism, but rather the circumcision of the New Testament. Notice how Paul referred to Christians in the following manner in Philippians 3:3, “for we are the true circumcision, who worship in the Spirit of God and glory in Christ Jesus and put no confidence in the flesh.” What gave Paul the right to refer to Gentile Christians in this manner? Paul’s process of reasoning was expounded beginning in Romans 2:17, climaxing with his words in Romans 2:28-29, “28 For he is not a Jew who is one outwardly; neither is circumcision that which is outward in the flesh. 29 But he is a Jew who is one inwardly; and circumcision is that which is of the heart, by the Spirit, not by the letter; and his praise is not from men, but from God.” New Testament circumcision is a circumcision of the heart.
The concept of a circumcised heart was both taught and commended in the Old Testament (Deut. 30:1-6) and was ultimately what was prefigured in physical circumcision. In other words, saints, physical circumcision was meant to be an illustration to the Jews of their need for regeneration, spiritual circumcision. Although the imagery was different, this referred to the exchange of a heart of stone with a heart of flesh affirmed in Ezekiel 36:24-27. This is the new birth. Notice how closely the two ideas of physical and spiritual circumcision parallel each other. Jeremiah 4:4 says to the people, “Circumcise yourselves to the Lord And remove the foreskins of your heart, Men of Judah and inhabitants of Jerusalem, Lest My wrath go forth like fire And burn with none to quench it, Because of the evil of your deeds.” In other words, Circumcision is the type of which regeneration, not baptism, is the true antitype (cf. Deut. 10:16; Lev. 26:41). The physical circumcision of the Old Testament is rightly replaced with the spiritual circumcision of the New Testament. This spiritual circumcision is a circumcision of the heart.
So then, in the Old Testament, circumcision of the flesh was the rite of entrance into the natural membership of Israel as a nation, as a political entity. It placed someone in the sphere in which they could potentially experience the blessings of the covenant. But even in the Old Testament the experience of these blessings was never placed within the reach of those who were circumcised alone. In other words, there had to be true salvation, true living towards God, before even the Old Testament blessings were experienced by a particular individual (Deut. 27-30). With the inauguration of the church, the new man, different from the old (Eph. 2:15), God made salvation the requisite for both entrance into the potential sphere of blessings and the basis of the actual experience of the blessings. Water baptism then is something new that corresponds to the fact that the church is neither Jew or Greek, but rather is a new man, a new entity. It has only one way of entrance, spiritual salvation. Water baptism is the external sign and confession that this spiritual circumcision has in actuality truly taken place. There is no biblical support for baptizing infants, even in the book of Acts, from which no evidence can be gleaned that people other than those who understand and responded to the gospel with faith were baptized (cf. 16:32-34).