You miss the point. The Bible says many things. However, the SUM of God's word means no one scripture explains everything relative to topics such as, believing in Jesus, water baptism, etc. Truth is revealed through study of ALL related scriptures.
An example, the Bible says, Jesus commanded His disciples to baptize in the name of the Father, Son and Holy Ghost. (Matt. 28:19) However, the truth concerning what He was talking about comes to light upon examination of how His apostles obeyed that command. There is not one scripture of His apostles using the phrase while water baptizing people. His apostles obeyed His command by invoking His name during water baptism. Also, not all scriptures mention that one's sin is remitted upon obedience. However, there are scriptures that explain the NT water baptism, preceded by repentance, was for the purpose of remitting sin in association with Jesus' sacrifice.