Did God command penitent believers to be baptized in order to be saved or because they already were saved? Most denominations teach the latter, but the Bible does not. The Bible gives three reasons why baptism saves.
Baptism saves because the Bible so states. The apostle Peter wrote, "Baptism now saves you" (1 Pet. 3:21). These words are as inspired by God as, "whoever believes in Him should not perish" (John 3:16). Many accept John's statement but not Peter's, yet Jesus said, "He who has believed and has been baptized shall be saved" (Mark 16:16). If belief saves, baptism does also.
Baptism saves because it puts one into the body of the saved. "The Lord added to the church daily such as should be saved" (Acts 2:47, KJV). Did the Lord leave any saved people out of the church? People are added to this same church when they are "baptized into one body" (1 Cor. 12:13), for this one body is the church (Eph. 1:22-23; 4:4). Since baptism puts one into the body of the saved, failure to be baptized leaves one where?
Baptism saves because it precedes newness of life. Paul wrote, "We have been buried with him through baptism into death, in order that as Christ was raised from the dead through the glory of the Father, so we too might walk in newness of life" (Rom. 6:4). Jesus was raised from the dead only after he first died and was buried. No person today can be raised to spiritual life until he or she first dies to sin and is buried or baptized in water.