InsanityBytes wrote a charming piece on baptism which you can (and should) read here. As I commented to her, I agree with most of what she wrote. Many of the other comments began to head in several different directions. There are some more things I want to say about baptism, but rather than trying to say them all in her comments section, I decided to say them here.
First, Christians can disagree about baptism without condemning one another. We can have different opinions about what baptism is, what it accomplishes, where and how it should be done, and so on. To use technical language, each Christian believes that he or she is orthodox (or correct) and that Christians who disagree are heterodox (or incorrect), but we do not accuse the heterodox of being heretics, hypocrites, or unbelievers. We have the same Lord and Savior. We will meet in the same new creation, where we will know and understand all truth and will be able to identify (without shame or embarrassment) who was wrong about what teachings in this world.
Why then continue to discuss baptism? Why not “agree to disagree” and remain silent? Because those Christians who misunderstand baptism are missing the fullness of a blessing God intends them to enjoy. Because of their misunderstanding, they are missing the peace and comfort that comes to them through their baptism.
The key question is: is baptism something we do for God or is baptism something God does for us? If baptism is a work we do for God, then it cannot be involved in our salvation, for we are saved by grace through faith and not by works (Ephesians 2:8-9). But Peter wrote, “Baptism now saves you” (I Peter 3:21). On Pentecost, to answer the question “what shall we do?” Peter answered, “Repent and be baptized every one of you in the name of Jesus for the forgiveness of your sins, and you will receive the gift of the Holy Spirit. For the promise is for you and for your children” (pardon a little throat clearing at that last phrase) (Acts 2:37-39). Mark 16:16 says, “He who believes and is baptized shall be saved, but he who does not believe will be condemned.”
Can God save people apart from baptism? Of course; God can do anything. Unbelief condemns; lack of baptism does not condemn. But God links salvation to baptism for a very important reason. Even the most faithful Christian sins, and we all need assurance of forgiveness that goes beyond our repentance and our faith. We all have bad days when we wonder if we have repented correctly and sufficiently; we all have times when we wonder if our faith is strong enough for us to be saved. If we were left only to measure our repentance and our faith by the way we feel or by the good works that we do, we would be left in doubt.
To rescue us from doubt, God gave us the gift of baptism. When the devil and the sinful world and the sin still within us accuse us and make us doubt our faith and our salvation, baptism is our escape. Because God has linked the promises of forgiveness, salvation, and eternal life to the blessing of baptism, we use baptism as our defense when we doubt or when others attack. The correct attitude is not, “I was baptized on a certain day,” but, “I am baptized.” Baptism is a state of grace under which each Christian lives in this world while looking forward to the life to come.