According to the regulative principle of worship to which we as Presbyterians adhere, nothing is permitted in worship except what is explicitly stated as lawful in scripture. We are not permitted to add our innovations to Sunday corporate worship. We are allowed to sing, pray, read and hear the word preached. We are not allowed to paint or hold raffles in church. This does not mean we are never allowed to do such things anywhere. It simply means that the Sunday worship service is not the time or place for such things, as it is specificially set aside for the worship of God(1 Cor. 16:2).
Credobaptists, who believe that the proper subject of baptism is one who is old enough and/or possesses sufficient cognitive sophistication to make a credible profession of faith, believe that those who baptize infants are inconsistent if they claim to adhere to the regulative principle of worship, because they deny that we are given explicit command in scripture to baptize infants, and therefore are not warranted in baptizing infants in church. I argue, however, that infant baptism is fully consistent with the regulative principle of worship because it is indeed explicitly commanded in scripture.
That infant baptism is explicitly commanded in scripture is clear from the relevant household baptisms. I refer to these as oikobaptisms and I see myself as an oikobaptist because the Greek word for household is "oikos", which in scripture includes children, and it is for this exegetical reason infants ought to be baptized.
The six oiko-baptisms of the New Testament:
1. The household of Cornelius (Acts 10:44-48; 11:13-18)
2. The household of Lydia (Acts 16:13-15)
3. The household of the Philippian jailor (Acts 16:30-34)
4. The household of Crispus (Acts 18:8; 1 Cor. 1:14)
5. The household of Stephanus (1 Cor. 1:16)
6. The household of Gaius (1 Cor. 1:14 – by implication)
We will see that throughout the Old Testament, the presence of children is included unless explicitly stated otherwise, so that we are justified in assuming that children are included when the word "oikos" is used unless explicitly stated otherwise, and that the LXX translates the Hebrew word for house or household as "oikos." There is clear continuity between its use in the LXX and its use in the NT. This does not mean that there are always children in every household baptism.
The text does not say whether or not there were, as credobaptists correctly point out. The point, however, is that in light of the use of the word oikos in the OT and according to the Semitic manner of speech and of thinking in terms of families rather than individuals, the authors of the NT would have explicitly excluded children from the "oikos" had the act been restricted to those old enough or cognitively sophisticated enough to make a credible profession of faith, and so the burden of proof is on credobaptists to produce a text which excludes children from the "oikos."
OCCURRENCES IN THE OLD TESTAMENT:
Gen. 7:1, 12:17, 18:19, 36:6, 45:8, 11, 18, 46:3, 31, 47:12, 50:7-8, 22 Exod. 1:1, Lev. 16:6, 11, 17, Num. 18:1, 31, Deut. 6:22, 12:7, 14:26, 15:20, 26:11, 34:30, Josh. 2:18, 6:25, 24:15, Jdg. 14:15, 15:6, 16:31, 18:25, 1 Sam. 1:21, 22:1, 2:30, 31, 9:20, 22:15, 16, 25:6, 27:3, 2 Sam. 2:23, 6:11, 21, 9:9, 14:9, 19:41, 21:1, 4, 1 Kgs. 2:31, 16:7, 18:18, 2 Kgs. 8:1, 2 Jer. 38:17, Neh. 1:6, Esth. 4:14, Isa. 7:17, Jer. 12:6
“In the New Testament passages concerning the salvation, conversion, or baptism of a house the children of every age must be included, firstly because ... ‘house’ can be supplemented by ‘all, whole’ or replaced by ‘all who are his, with-all-the-house;’ secondly because in several passages the customary formula ‘he and his (whole) house’ is found, which in the Old Testament usage ... includes children, in fact has them particularly in view” (Jeremias, p. 16).
“The relevant datum is not the number of baptisms that occurred but the number of occurrences that were recorded. Excluding the baptism of John and of Jesus’ disciples, this latter count is a modest twelve. That three or perhaps four of these involved ‘households’ shows that the practice of baptizing households must have been rather frequent in apostolic times; and it is indeed true that many of those households must have included children and infants … Not that there were infants and small children in each case of recorded household baptism; but under no circumstance could Luke have used the ‘household formula’ had he wished to say that only adults were baptized” (Paul K. Jewett on Jeremias’s argument; Infant Baptism and the Covenant of Grace [Grand Rapids: Eerdmans, 1978], pp. 48,
To our baptist brethren, therefore, we argue that the New Testament does tell us to baptize infants and so we violate neither scripture nor the regulative principle of worship which it outlines. The credobaptist is encouraged to look at the relevant Old Testament passages cited. Once again, that infants are not explicitly mentioned in the NT household baptisms is not a point that needs to be made in order to defend the oikobaptist position. The point is rather that the authors of the NT would have gone out of their way to exclude children from this "oikos formula" had they intended infants to be excluded, since, apart from explicit exclusion, it is taken for granted that infants are included.
Heb. 11:7 "By faith Noah, being warned by God about things not yet seen, in reverence prepared an ark for the salvation of his house, by which he condemned the world, and became an heir of the righteousness which is according to faith."