Baptism saves you

In 1 Peter 3:18-22, we read that there is an anti type that saves us, that is, baptism.  This verse generates a great deal of verbal, linguistic and grammatical gymnastics.  People do not want this verse to mean what it says because it seems to speak contrary to the Lutheran/Calvinistic mantra of salvation by faith alone, sola fide.
Possibly the greatest stumbling point in this regard is the meaning that is often affixed to baptism.  The evangelical world wants to disembowel the word and reduce it to a public profession of faith.  But obviously this is clearly contrary to 1 Peter 3:21.
As you can probably guess, I am going to argue for the historic meaning of the text.  Baptism is a sacrament that actually does something.  As a sacrament, baptism identifies us as part of the body of Christ.  Similar to the Old Covenant mark of circumcision, baptism is the New Covenant "mark" as belonging to the people of God. It is very helpful to consider circumcision when seeking to understand baptism.  In the Old Covenant, if someone wanted to be part of the people of God, they needed to accept the covenant sign.  Did the covenant sign save them? In a sense, yes, but only if they were faithful.  Consider the Day of Atonement.  The high priest would enter the holy of holies once a year and offer up sacrifices for all the people.  If he emerged from the tabernacle alive, then it meant that God accepted his sacrifice.  This means the sins of all the people were covered. All of them for all of them.  But we know full well that not all of the Israelites entered the Promised Land.  Many of them died in the wilderness.  In other words, some went to heaven and some didn't.
This same pattern holds true for the New Covenant believer. If someone wants to be part of the body of Christ, he must be baptized into the church, the body of Christ.  Does this save him? In a sense, yes, as long as he is faithful and perseveres to the end.  Having a right understanding of the nature of baptism will truly help one rightly understand this passage.
Baptism saves us as it is "the" means of entering into right relation with the body of Christ.  It is into Christ that we are being baptized and life is only in him.  But we only attain eternal life in and with Christ when we are faithful and persevere in the faith to the end.