Here's some of my thoughts on this passage concerning baptism:
1 Peter 3:18-22 --
18For Christ died for sins once for all, the righteous for the unrighteous, to bring you to God. He was put to death in the body but made alive by the Spirit, 19 through whom also he went and preached to the spirits in prison 20 who disobeyed long ago when God waited patiently in the days of Noah while the ark was being built. In it only a few people, eight in all, were saved through water, 21 and this water symbolizes baptism that now saves you also--not the removal of dirt from the body but the pledge of a good conscience toward God. It saves you by the resurrection of Jesus Christ, 22 who has gone into heaven and is at God's right hand--with angels, authorities and powers in submission to him.
**emphasis mine**
The first part I put in bold is, I think, the most base fact: that Christ died once for all sins. He didn't die several times. He doesn't die continually. He isn't still dying for our sins. He did it once. And after He died, He came back to life. He is living. He is not continually dying for our sins, but continually living because He has already died for them once and for all.
In the next few verses, Peter compares baptism to Noah's ark. He says that in the ark, Noah and his family were saved through water, and this water symbolizes baptism that saves us also.
But then Peter makes an important distinction. He says that baptism saves us, "not the removal of dirt from the body but the pledge of a good conscience toward God."
So here we have two different thoughts on what baptism might possibly do.
1) Removal of dirt from the body. This means sin in this context.
2) The pledge of a good conscience toward God. This would be more of a turning of will or spiritual belief.
Now, let's continue the comparison to the ark that Peter set up.
The removal of dirt from the body:
In Noah's day, the world was filled with sinful people. They were so terrible that God decided to wipe out mankind.
Genesis 6:5-8 --
5 The LORD saw how great man's wickedness on the earth had become, and that every inclination of the thoughts of his heart was only evil all the time. 6 The LORD was grieved that he had made man on the earth, and his heart was filled with pain. 7 So the LORD said, "I will wipe mankind, whom I have created, from the face of the earth-men and animals, and creatures that move along the ground, and birds of the air-for I am grieved that I have made them." 8 But Noah found favor in the eyes of the LORD.
Noah was the only who seemed to be living a God-focused life. So God commanded Noah to build a big boat so that he and his family (just eight people) could be spared the destruction. God gave him all the specifications. And Noah just did it. He was just a farmer. He might not have ever been in a boat, much less built one before. But Noah loved the Lord and lived by faith.
And so Noah and his family were saved in the ark. But Peter doesn't say that it was just the ark that saved them. Peter said that in the ark they were saved "through water."
The water washed the dirt from the body. Noah was the last one left living a Godly life. It's not like God was only passed down through one branch of every family. The wickedness in the world was continually corrupting faith in God. Noah was the last chance. So the wickedness was a direct threat, not only to Noah's family's faith in God, but to their lives as well. So in flooding the planet, God saved Noah's family from the threat of the surrounding wicked people.
Peter compares this with washing away sins calling it washing dirt from the body. In the Noah example, the dirt would equal the wicked people and the body would equal the earth. But if we wash dirt from ourselves we can always get dirty again. Sin and wickedness still spread through the world by Noah's descendants. Even though the direct threat of the surrounding wicked people had been removed, sin still stayed on earth.
The pledge of a good conscience toward God:
So Noah was saved by the water that removed the direct threat of wicked people. But the water --the very force by which the rest of the population was destroyed-- saved Noah in another way also. It kept him afloat.
See, God didn't just tell Noah, "I'm gonna flood the whole planet but I'll spare you and your family." God also gave him something to do to take part in the rescue. God said, "so I want you to build an ark."
The flood surely saved Noah by washing the dirt from the body-- all the wicked people. But God also offered Noah a chance to escape similar destruction. God asked for the faith and trust to do precisely what He said on a job which Noah was likely completely inexperienced. God was warning about the impending destruction but at the same time offering Noah a plan for salvation. All Noah had to do was have faith and trust in God.
And that's the part of the deal that Peter seems to be stressing as important: the pledge of a good conscience toward God. The world was made safe by getting rid of the evil people... but only for a while. That kind of temporary safety is not the kind of salvation that God is offering us in the Gospel.
Just like in Noah's day, God is warning us of the impending destruction. And just like in Noah's day, God is offering a plan for our salvation. And just like in Noah's day, all we have to do is have faith and trust in God. In Noah's day that meant building an ark. For us it means trusting in Jesus Christ. This is the pledge of a good conscience Peter was talking about. This is the baptism that saves us. It's not the water. It's not the washing of dirt from the body. We don't even need to worry about our "dirt." Christ already died for our sins. The baptism that saves us is the faith in Jesus Christ as the Son of God, Lord of Lords and King of Kings.
That is the baptism that saves us.
I think the only conclusion to seeing baptism as the visible word is to hold to baptismal regeneration. QUALIFICATION: Not understanding baptismal regeneration in the way the Roman Catholics (ex opere operato) nor the Church of Christ do. Both of those groups do not accept justification by faith alone. But I see it in a reformation way, that baptism is the gospel and the gospel regenerates. "For you have been born again, not of parishable seed, but of imperishable, through the living and enduring word of God." 1 Pet 1:23 As Augustine reminds us, water by itself is just water, but add the word of God to it and it becomes a sacrament; the "washing of water with the word" (Eph 5:26). Baptism continues to renew us throughout our lives (a daily drowning the old Adam), as Luther put it. Baptism also gives and strengthens faith, as does the preached word. So given that it regenerates and gives and strengthens faith, I would say that baptism saves.
