Q 163 What are the parts of a sacrament?

A. The parts of the sacrament are two; the one an outward and sensible sign, used according to Christ’s own appointment; the other an inward and spiritual grace thereby signified.[1056]

[1056] Matthew 3:11. I indeed baptize you with water unto repentance: but he that cometh after me is mightier than I, whose shoes I am not worthy to bear: he shall baptize you with the Holy Ghost, and with fire.

1 Peter 3:21. The like figure whereunto even baptism doth also now save us (not the putting away of the filth of the flesh, but the answer of a good conscience toward God,) by the resurrection of Jesus Christ.

Romans 2:28-29. For he is not a Jew, which is one outwardly; neither is that circumcision, which is outward in the flesh: But he is a Jew, which is one inwardly; and circumcision is that of the heart, in the spirit, and not in the letter; whose praise is not of men, but of God.