Acts 2:38

38. Repent Literally, change your minds, namely, from your guilty hostility to Christ to a full faith in his name. In its full Christian sense repentance includes a perfect and saving faith in Christ.

Repent, and be baptized By repentance they renounce their hostility to the crucified One, and all the sins that slew him; by baptism they are accepted into the body of his friends; and by the gift of the Holy Ghost they become truly one with the sanctified hundred and twenty, (Acts 2:1,) and are empowered to do mighty wonders in behalf of Christ the exalted Lord.

For the remission of sins Baptism is the external act and manifestation of an internal justifying faith already existing. As the outward act and manifestation of the conditional faith, baptism is mentioned before that remission which follows the internal faith, although the instant divine act of remission has actually preceded the baptism. Internal faith precedes the divine act of remission; while the external baptismal act of faith is the organic condition to the normal state of remission. Hence only the justified person is rightly baptized. The infant is baptized as a virtual, and the adult as an actual believer. From all this it would follow that a wilful neglect of baptism, where no impossibility exists, endangers the permanence of the remission, and so of the salvation. To the question whether a justified, unbaptized person may rightfully commune at the Lord’s Supper, we should reply that it is the wrong order; nevertheless, the wrong consists not in the communing, but in the omission of a previous baptism. Baptism externally brings us into the Church; communion testifies that we are in the Church.