Some argue that 1 Peter 3:21
For Christ also suffered once for sins, the righteous for the unrighteous, that he might bring us to God, being put to death in the flesh but made alive in the spirit, in which he went and proclaimed to the spirits in prison, because they formerly did not obey, when God's patience waited in the days of Noah, while the ark was being prepared, in which a few, that is, eight persons, were brought safely through water. 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, who has gone into heaven and is at the right hand of God, with angels, authorities, and powers having been subjected to him. (1 Peter 3:18-22
The argument is that 1 Peter 3:21
The question, "Is baptism necessary for salvation?", is misleading. We believe that baptism is "necessary" for salvation in that baptism is commanded by God, and thus one who refuses baptism demonstrates a lack of true saving faith. A better question to use for framing this debate is, "At what point is a person saved: upon having faith, or upon being baptized?"
The key issue is not these individual passages, but rather, answering the question, "Does the Bible teach that salvation is through faith alone?" If the answer to that question is "Yes," then the question is, "What exactly does it mean to be saved through faith alone?"
The value in debating these individual passages is simply to demonstrate that they do not contradict the doctrine of salvation through faith alone. However, we do not build our theology of salvation upon these individual passages. They are peripheral to the key issue, which is the doctrine of salvation through faith alone.
We simply need to continue reading in 1 Peter 3:21
So, Peter is saying that the baptism he is describing does not actually remove dirt from the body, but actually represents belief, or faith,, or "an appeal to God."
The key to understanding 1 Peter 3:21