There are many religions that believe that baptism is required for salvation. That is false. Many will quote that Mark 16:15 states that whoever that states "The one who has believed and has been baptized will be saved; but the one who has not believed will be condemned." A lot of people take this out of context.
The problem was this premise is that in the second of half of the verse, it doesn't mention Baptism as a qualifier. Let's make one thing very clear, Jesus told the thief on the cross, "Today you will be with me in paradise." They DI NOT take the thief down to be baptized. Jesus Christ is the same yesterday, today, and forever. He is not going to make an exception this one time, because if you really believe that you HAVE to be baptized in order to be saved, then the thief on the cross went straight to hell, which would make Jesus a liar.
Baptism represents the death, burial, and resurrection and is a work. Ephesians 2:8-9 is very clear on this matter. "For by grace you have been saved through faith; and this is not of yourselves, it is the gift of God; not a result of works, so that no one may boast." You are baptized because you have been saved, NOT in order to be saved.
Surely one couldn't say that Jesus Christ who was baptized by John the Baptist would have gone to hell if he had skipped that part of baptism. Baptism has always represented one who has come to Christ and took the next step. Jesus was baptized as an example, not a requirement. There have been many deathbed confessions who were not baptized, but still went to heaven because they did not have the opportunity to be baptized. To say that you have to be baptized in order to be saved is to openly admit that no one in the Old Testament will go to heaven.
A person who goes into the waters of baptism lost (without salvation) will come out as a lost sinner. Baptism is an ordinance and is a work of the church. As stated above, baptism is a work performed by man and therefore contradicts Ephesians 2:8-9.