1 Pet. 3:21 says, "And corresponding to that, baptism now saves you - not the removal of dirt from the flesh, but an appeal to God for a good conscience - through the resurrection of Jesus Christ." This is the only verse that says "baptism now saves you." But, is it teaching that we must be baptized in water to be saved? No. But, but to rightly understand it, we need to look at its context.
"For Christ also died for sins once for all, the just for the unjust, in order that He might bring us to God, having been put to death in the flesh, but made alive in the spirit; 19 in which also He went and made proclamation to the spirits now in prison, 20 who once were disobedient, when the patience of God kept waiting in the days of Noah, during the construction of the ark, in which a few, that is, eight persons, were brought safely through the water. 21 And corresponding to that, baptism now saves you - not the removal of dirt from the flesh, but an appeal to God for a good conscience - through the resurrection of Jesus Christ, 22 who is at the right hand of God, having gone into heaven, after angels and authorities and powers had been subjected to Him," (1 Pet. 3:18-22).
The above translation in verse 21 from the NASB is a good translation: "and corresponding to that, baptism now saves you." The key word in this section is the Greek antitupon. It means "copy," "type," "corresponding to," "a thing resembling another," "its counterpart," etc. It is what the NIV translates as "symbolizes," the NASB as "corresponding to that," and the KJV as "like figure." Baptism, then, is a representation, a copy, a type of something else. The question is "Of what is it a type?" or "baptism corresponds to what?"
If we look at the context, an interesting possibility arises. What does baptism correspond to? Is it the flood? Or, is it the ark? What was it that saved Noah and his family - the flood or the ark? Obviously, it was the Ark. Noah built and entered the ark by faith, and he was saved (Heb. 11:7). The floodwaters destroyed the ungodly. Also, Peter consistently refers to the floodwaters as the means of destruction of the ungodly (2 Pet. 2:5; 3:6) - not the salvation of Noah and his family. Rather, it was the Ark that saved - the ark that Noah entered by faith. It may very well be that baptism refers to the Ark - not the waters which may be why the rest of the verse says, "not the removal of dirt from the body but the pledge of a good conscience toward God," which is consistent with what Paul said in Col. 2:11-12 where he equates baptism with being circumcised of heart. In other words, Peter clarifies that it isn't the water baptism that saves but the appeal to the heart.
But, to be fair, the Greek seems to imply that the baptism is referring to the water - not the ark, due to the proximity of the antecedent. Still, we need to consider this and make some observations. If we were to look at the floodwaters as the thing that removed evil from the land, we could say that "correspondingly" the waters of baptism removes the sin from our hearts. Though this reading seems a bit more natural, it, too, as problems.
The water of baptism is not what saves us; the sacrifice of Christ does that when we receive Him by faith. We read numerous verses about justification by faith (Rom. 5:1), salvation by faith (Eph. 2:8), etc., not justification "by faith and baptism" or salvation "by faith and baptism." The fact is that salvation is received by faith. Peter, not wanting to declare that baptism itself is what saves us, quickly adds, "not the removal of dirt from the flesh, but an appeal to God for a good conscience." Water baptism, then, must accompany the work of the Holy Spirit in the person. Peter's explanatory comment shows us that the act of physical baptism is not what saves but the "baptism of appeal to God." This appeal to God is by faith the same as Noah's faith in God led him to build the Ark, enter it, and remain in it. It was the Ark that saved Noah - not the floodwaters.
The flood was for Noah a type of baptism even as the passage through the Red Sea was a type of baptism for the Israelites.
"I want you to know, brethren, that our fathers were all under the cloud, and all passed through the sea, 2 and all were baptized into Moses in the cloud and in the sea, 3 and all ate the same supernatural food 4 and all drank the same supernatural drink. For they drank from the supernatural Rock which followed them, and the Rock was Christ," (1 Cor. 10:1-4).
The "baptisms" of both Noah and the Israelites served as types of a transition; that is, they moved people from the old world to the new - from the old covenant to the new covenant. It is not the water that saves but the spiritual thing associated with that water that saves. For Noah, it was faith in God. For Moses, it, too, was faith in God.
But some may say that the work of the Holy Spirit and the act of baptism are simultaneous - that the Holy Spirit works in and through baptism to bring regeneration. But this cannot be the case since the Bible tells us that salvation is by faith (Rom. 5:1; Eph. 2:8). Besides, we have a clear instance in scripture where people are saved before their baptism.
"While Peter was still speaking these words, the Holy Spirit fell upon all those who were listening to the message. 45 And all the circumcised believers who had come with Peter were amazed, because the gift of the Holy Spirit had been poured out upon the Gentiles also. 46 For they were hearing them speaking with tongues and exalting God. Then Peter answered, 47 "Surely no one can refuse the water for these to be baptized who have received the Holy Spirit just as we did, can he?" 48 And he ordered them to be baptized in the name of Jesus Christ. Then they asked him to stay on for a few days," (Acts 10:44-48).
In these verses, we see that Peter had been preaching the gospel, and the Holy Spirit fell upon the listeners. In verse 45 we read that "the gift of the Holy Spirit had been poured out upon the Gentiles also." This gift manifested itself in speaking in tongues. This is significant because tongues is a sign-gift given to believers - see 1 Cor. 14:1-5. Also, verse 46 says they were "exalting God." Unbelievers don't praise God. They can't because praise to the true God is a deeply spiritual matter that is foreign to the unsaved (1 Cor. 2:14). Therefore, the ones in Acts 10 who are speaking in tongues and praising God are definitely saved because they are moving in the Holy Spirit, speaking in tongues, and glorifying God. It is the Holy Spirit who gives charismatic spiritual gifts to the church (1 Cor. 12:27-28) and not to unbelievers. Now, please notice that it was after this movement of the Holy Spirit that the believers are baptized. If baptism is necessary for salvation, then how is it that the people were speaking in tongues and exalting God before they were baptized?
If you were to say that the Holy Spirit was simply working upon and through those not yet saved, then remember that tongues and praise to God are for the church--not the unbelievers. The church consists of people who are saved--not unsaved. If they were not saved until they were baptized, then they were not in the body of Christ and would not have moved in the charismatic gifts. Therefore, they were regenerate before they were baptized. This simply isn't an exception. It is a reality.
1 Pet. 3:21 is not teaching us that baptism is what saves us. Rather, it is showing us that the water symbolizes a spiritual cleansing through the power of the Holy Spirit gained through Christ's victory over death. It is the person's appeal to God that saves the soul--not the washing of water upon the body.