1689 LBCF ch. 29: Of Baptism

Baptism is an ordinance of the New Testament, ordained by Jesus Christ, to be unto the party baptized a sign of his fellowship with him in his death and resurrection. Those who do actually profess repentance toward God, faith in and obedience to our Lord Jesus Christ are the only proper subjects of this ordinance. Immersion in water is necessary to the due administration.