New Testament Baptism draws from a number of Old Testament sources for its significance. We know that it cannot be entirely new to the New Testament; for one thing, John’s baptism was immediately connected to the coming of the Messiah by the Jews.
The Old Testament prescribes cleansing water rituals for a variety of situations. They were performed when someone became ritually unclean (see Numbers 19) or when priests began their service in the temple (Leviticus 8) involving symbolic baths or washings, including sprinkling of water. In Mark 7:4 these kinds of washings, superstitiously performed constantly by the Jews and even applied to vessels and furniture, are referred to by the Greek word for “baptism”. The water rituals signified being “sanctified,” or set apart, made holy for the service of God.
These sprinklings of water also call to our mind the sprinkling of blood in the ceremonial law, because both the ceremony and the meaning behind it are similar. Blood from sacrifices was sprinkled on the altar, on the Ark of the Covenant and on the people as a symbolic covering of sin. In Hebrews 9, the writer describes these ceremonies of the old law as “shadows,” pointing us forward to the reality found in Christ. He says the copies, or symbols, of heavenly realities are sanctified or made holy in this way, but that the reality is in Christ’s blood. Then, after making this point in Hebrews 10, he calls on us to have boldness in the New Covenant, recognizing that we are now “sprinkled from an evil conscience and our bodies washed with pure water.” The reference to baptism is clear.
Baptism is also connected thematically to circumcision in Colossians 2- the circumcision made without hands, which we have in Christ, is said to come to us through baptism. Circumcision in the Old Testament points us to the need to cut off our pride and put our trust in God, a truth that finds its ultimate expression in the sacrifice of Christ, who was cut off for the sins of His people. Just as circumcision united a person to Israel, so baptism unites a person to the church, the body of Christ.
In both Baptism and the Lord’s Supper, we see a great deal of Old Testament symbolism simplified and divorced from its more carnal and temporary elements and presented to us purely and spiritually. Baptism sweeps up all these ancient themes- forgiveness, sanctification, consecration. We baptize a person when God brings him within the sphere of the visible church, either by confession of faith or by birth. By that baptism God visibly and outwardly unites him to the church and places the promises of the gospel visibly on him, calling him to faith in that gospel. Our baptism is a reminder to us throughout our lives of the gracious salvation which God’s people are promised through the death of Christ, that just as water washes us from dirt, so we are washed from sin by the blood of Christ and the power of the Spirit.
These are the three that bear witness on earth- the Spirit, the water and the blood, all united in the sacrament of baptism. By that reminder, God works grace in the hearts of His people throughout their lives, and therefore the Apostle Peter says that we are “saved by baptism” (1 Peter 3:21)- not that the ceremony by itself can save us, but that united with the election of God and the power of the Spirit, baptism becomes a powerful means by which God brings His people home finally to Himself, to serve Him as priests and kings forever.