John preached an immersion of repentance for the forgiveness of sins. The immersion ritual itself was not sacramental; it did not accomplish the forgiveness of sins. Instead, repentance brought the forgiveness of sins. The penitent’s immersion into water merely symbolized his or her sincere, heartfelt repentance.
The Torah never requires immersion as a component of repentance. Immersion in water accomplishes ritual purification, but the Torah does not prescribe it as a repentance-ritual. In rabbinic thought, however, ritual immersion can symbolize the spiritual washing obtained by true repentance. A later rabbinic parable illustrates how ritual immersion could be analogous to repentance:
One who commits a sin and confesses it but does not turn away from the sin, to what may he be compared? He can be compared to a man holding a dead lizard [which causes ritual uncleanness] in his hand. Even if he immerses himself in all the water in the world, his immersion will not purify him. But if he throws the lizard away from his hand, then if he immerses only in forty se’ahs of water, his immersion is immediately efficacious for him, as it says [in Proverbs 28:13], ‘He who confesses and forsakes [his transgressions] will find compassion.’” (Talmud)
The Bible often uses the language of Levitical purification to speak of repentance and forgiveness. “Wash me thoroughly from my iniquity and cleanse me from my sin” (Psalm 51:2), David prays, “Purify me with hyssop, and I shall be clean” (Psalm 51:7). “Wash your heart from evil, O Jerusalem, that you may be saved,” Jeremiah says (4:14). The Apostle Peter reminds us that immersion is “not the removal of dirt from the flesh, but an appeal to God for a good conscience” (1 Peter 3:21), an interpretation consistent with the words of Isaiah:
“Wash yourselves, make yourselves clean; remove the evil of your deeds from My sight. Cease to do evil, learn to do good; seek justice, reprove the ruthless, defend the orphan, plead for the widow. Come now, and let us reason together,” says the LORD, “Though your sins are as scarlet, they will be as white as snow; though they are red like crimson, they will be like wool.” (Isaiah 1:16-18)
The prophets of Israel taught that God will spiritually wash His people at the time of the Messianic Era. “I will sprinkle clean water on you, and you will be clean; I will cleanse you from all your filthiness … I will give you a new heart and put a new spirit within you” (Ezekiel 36:25-26). He will forgive their sins and create within His people a new, upright, and obedient heart. Those prophecies invoked the rubrics of ritual purity rituals, including the washing with water. As a preacher of the imminent arrival of the kingdom of heaven, John called people to lay hold of that messianic, spiritual cleansing immediately.