John Calvin Commentary Acts 10:47

"Can any man forbid the water, that these should not be baptized, who have received the Holy Spirit as well as we?" — Acts 10:47 (ASV)

Peter answered. Peter reasons from the reality to the sign; for, since baptism is an addition or accompaniment of spiritual grace, he who has received the Spirit is also fit to receive baptism. This is the most lawful order: that the minister admit to the receiving of the outward sign those whom God has testified to be His children by the mark and pledge of His Spirit, so that faith and doctrine are first.

And while unlearned men infer from this that infants are not to be baptized, it is entirely without reason. I grant that those who are strangers to the Church must be taught before the sign of adoption is given to them; but I say that the children of the faithful who are born in the Church are, from their mother’s womb, of the household of the kingdom of God. Indeed, the argument they absurdly use against us, I turn back upon them; for, since God has adopted the children of the faithful before they are born, I conclude from this that they are not to be deprived of the outward sign. Otherwise, men would presume to take from them what God has granted them. Regarding the manifest grace of the Spirit, there is no absurdity in it following after baptism in them.

And just as this testimony does nothing to support their error, so it strongly refutes the error of the Papists, who tie the grace of the Spirit to the signs and think that it is fetched from heaven with enchantments, just as those witches thought they pulled down the moon with their charms. But since Luke says that these had the Holy Ghost given to them who were not yet baptized, he shows that the Spirit is not included in baptism.

Lastly, we must note that the apostles were content with water alone when they baptized. I wish to God this simplicity had been retained among their posterity, and that they had not gathered here and there various trifles, because of which baptism is corrupted in Popery. They think that the dignity of baptism is adorned with oil, salt, spittle, and wax candles, while instead they are filthy pollutions that corrupt the pure and genuine institution of Christ.