HC 72

Heidelberg Catechism

Q72. Does this outward washing with water itself wash away sins?

No, only the blood of Jesus Christ and the Holy Spirit cleanse us from all sins.

Matt. 3:11 — [11] “I baptize you with water for repentance, but he who is coming after me is mightier than I, whose sandals I am not worthy to carry. He will baptize you with the Holy Spirit and fire.
1 Pet. 3:21 — [21] Baptism, which corresponds to this, now saves you, not as a removal of dirt from the body but as an appeal to God for a good conscience, through the resurrection of Jesus Christ,
1 John 1:7 — [7] But if we walk in the light, as he is in the light, we have fellowship with one another, and the blood of Jesus his Son cleanses us from all sin.

The Assembly cited Matt. 3:11 in support of this answer. Read it in context — how does it bear on what is claimed here?
3 passages are cited here. Which does the most work, and is anything claimed that the proofs do not obviously carry?
WSC Q88 treats the same ground. What does it add, and why might it put things differently?
WLC Q149 treats the same ground. What does it add, and why might it put things differently?