Baptism is mentioned in several ways in the Bible. There is the baptism of repentance, the baptism of fire, the baptism of the Holy Spirit, the baptism of Moses, baptism for the dead, baptism of suffering, water baptism, etc.  Ephesians 4:4-6 says there is one baptism. Since the Bible is without error or contradiction, we must conclude that the one baptism is the baptism commanded by the Lord and the apostles and the one in effect today. This one baptism (water immersion in the name of Jesus Christ for the remission of sins) is plainly shown in examples throughout the New Testament where believers were converted.