The term used in Greek is antitype. The addition of the preposition “anti” is significant. A “type” (Greek: tupos) conveys the notion of “likeness,” so that had Peter used the word “type” he would have implied a similarity or parallel between (the water of) the flood and (the water of) baptism. By using the word “antitype” Peter sets up a contrast between the flood and baptism, so that while the waters of the flood destroyed, the waters of baptism save. Significantly, the Lord used the deadly flood waters to save Noah from the apostasy of his corrupt world.
21 Baptism, which corresponds to this, now saves you, not as a removal of dirt from the body but as an appeal to God for a good conscience, through the resurrection of Jesus Christ,