The Apostle Peter teaches us that baptism doesn’t clear dirt off the body, but it is a pledge––an answer––of a good conscience toward God (1 Pt. 3:21). Outside of Christ, the conscience is a ceaseless drone of accusation and guilt. It bears witness against you that you’re a rebel against God and grace. You deserve to be swept away in a flood of His wrath.
But baptism into Christ is a salvation from that guilty conscience. Baptism not only points to Christ’s death for our sin (by receiving God’s wrath), but His resurrection from the death which the curse of sin brought into the world. Those who are in Christ receive a covenant sign of that entry into Him. They hold up their baptism as an answer to the question, “How can you––a sinner––be justified in God’s eyes?” The answer of their baptism is: “Because Jesus died––the just for the unjust (1 Pt. 3:18)––and rose from the dead; and by faith, I am in Him.”
All baptized believers have an answer to give when asked for the reason of the hope that is in them (1 Pt. 3:15). Their answer is their baptism. Guilty consciences are promised a good conscience when they look to Christ alone and thus enter into His death and life. So hold up the only hope of a good conscience towards God: the righteous Son of God.