1 Peter 3:21

The antecedent of "that" seems to be "water" (1 Peter 3:20). Baptism saves Christians now as the water that floated Noah’s ark saved him and drowned his unbelieving antagonists. It does not save us by cleansing us from defilement, either physically or spiritually, but by announcing publicly that the person baptized has placed his or her faith in Jesus Christ. Baptism now delivers (saves) us from the consequences of siding with the world (cf. James 1:21; James 2:24; 2 Corinthians 6:17-18; Colossians 3:8-9; Hebrews 10:22). Baptism is the evidence that a person has made a break with his or her past life and is taking a stand with the Savior. It is a pledge (translated "appeal" in the NASB) springing from a good conscience (i.e., a conscience that is now right with God; cf. 1 Peter 3:16). [Note: Hiebert, "The Suffering . . .," pp. 154-56.]

". . . they have already experienced salvation in the same way Noah did, namely by passing through water to safety, the water of baptism (cf. the similar analogy in 1 Corinthians 10:1-2)." [Note: Davids, p. 143.]

"Corresponding to" (1 Peter 3:21) is a translation of the Greek word antitypon ("antitype"). This is one of the places in the New Testament where the writer identified something as a type (cf. also Romans 5:14; 1 Corinthians 10:6; 1 Corinthians 10:11; Hebrews 9:24). The flood in Noah’s day is a type (i.e., a divinely intended foreshadowing) of baptism.

Peter’s point in his comments about baptism was this. In water baptism his readers had made a public profession of faith in Christ in their community. This had led to persecution. However by that act of baptism they had also testified to their ultimate victory over their persecutors. Because they had taken a stand for Jesus Christ they could be sure that He would stand with them (cf. 2 Timothy 2:12).

Many people who hold to infant baptism appeal to this verse in support of their belief. Most Lutherans, for example, believe that infant baptism guarantees the salvation of the child until he or she becomes old enough to make the faith of his parents, expressed in having their baby baptized, his own (cf. Matthew 28:19; Mark 16:16). In infant baptism the Lord bestows on the child "a good conscience toward God," which is the evidence of salvation. [Note: See Lenski, pp. 172-73.] At about 12 years of age, Lutheran children go through instruction to "confirm" them in the faith. Lutherans believe that infant baptism guarantees the salvation of children if they die before making their parents’ faith their own. They see a parallel with circumcision in the Old Testament. Roman Catholics and many Presbyterians also baptize infants for the same purpose.

The problem with this interpretation, from my viewpoint, is that Scripture nowhere else makes baptism a condition for salvation. In fact, it consistently warns against adding anything to faith for salvation. Circumcision did not save children under the Old Covenant any more than baptism does under the New Covenant. Circumcision expressed the faith of the parents. Abraham received the sign of circumcision to demonstrate his faith on the male members of his household (Genesis 17).