Baptism is not to be administered to any that are out of the visible church, till they profess their faith in Christ, and obedience to him[a]; but the infants of such as are members of the visible church are to be baptized[b].
a:
Acts 8:36-37
Acts 2:38
b:
Acts 2:38-39
Genesis 17:10
Colossians 2:11-12
1 Corinthians 7:14