What Is Baptism?

Baptism is a sign. We grasp what it’s a sign of when we locate baptism within the unfolding of biblical history. Extrapolating from apostolic example, the church fathers see baptism as the reality foreshadowed by the waters of creation and Eden, by Noah’s flood (cf. 1 Pet. 3:18–22), Israel’s exodus through the sea (cf. 1 Cor. 10:1–5), by Joshua’s river-passage into Canaan, Elijah’s drenched sacrifice and Elisha’s floating axe head, by the cleansing of the Syrian commander Naaman in the Jordan. Scholastics are less effusively poetic, but they too discuss the “Sacraments of the Old Law” before turning attention to the “Sacraments of the New Law,” and various Protestant traditions do the same with the categories of old and new covenants. 

This was partly a game of compare-and-contrast. Circumcision was a preparatory figure of baptism, Thomas Aquinas says (Summa theologiae III, 70, 1), citing as proof Colossians 2, where Paul writes, “you are circumcised with a circumcision made without hands . . . in the circumcision of Christ, having been buried with him in baptism.” Baptism is “the sacrament of faith,” by which the baptized is “aggregated to the congregation of the faith.” So too circumcision was a “protestation of faith” that allowed “men of old” to be “aggregated to the body of the faithful.” 

Circumcision and baptism aren’t, of course, identical in every respect. Circumcision removed “a carnal pellicule,” while baptism strips off the flesh that works immorality, impurity, idolatry, strife, anger, envy, and drunkenness. Circumcision physically represents baptism’s “spiritual effect” (III, 70, 1). Circumcision was for Israel alone, while baptism is binding on all nations. Baptism is universal, Thomas says, because it contains the “perfection of salvation,” while circumcision signified the perfection that would come through the Jewish Messiah (III, 70, 2). Circumcision bestowed grace, but not as baptism does. Baptism’s superior power comes from Christ’s consummated Passion, while circumcision was effective by symbolizing the Passion to come (III, 70, 4).

Thomas’s final comment hints at something more subtle than simple comparison. The difference in signs is determined by a difference in reality. Augustine illustrates the distinction between old and new grammatically, by pointing to the conjugation of Latin verbs. The participle resurrecturus indicates a future triumph over death, while the verb resurrexit names resurrection as a past event. The root is the same; only the ending changes. The words differ by a matter of a few letters, but that slight change in form produces a radical difference in meaning. Just so, sacramental signs share a common “root” but change with the times. Circumcision and baptism both embody God’s promise, but at different stages of fulfillment. As a future-tense rite, circumcision signifies Israel’s hope; the present-tense sacrament of baptism spells hope accomplished.

Once we start thinking about baptism in the matrix between old and new, our horizon broadens. Rather than narrow our focus to the effect of baptism on an individual, we can ask what baptism says about the world. It’s a sign of the new covenant, which by its very existence tells us we live in the new world born from the advent of the Son and Spirit. What is baptism? Baptism is a ritual clock. It tells what time it is.

Christians have always protested against the idea that the sacraments are “mere” or “empty” signs. No nuda signa, Calvin insists. Through the power of the Passion of the Son and the energy of the Spirit, baptism makes new covenant realities real. As a sign of the new covenant, baptism brings the new covenant to actuality. Baptism doesn’t just picture the union of Jews and Gentiles in one body; it unites them, and so brings the fulfilled promise of the new covenant into concrete, earthly reality. Baptism doesn’t just tell us there’s a new priesthood somewhere; as the initiation rite for priests, it forms the priesthood. Baptism doesn’t just portray a new Israel following the new Joshua across the Jordan; it musters the new-Israel army. 

Baptism is God’s present-tense declaration that he has fulfilled the law and the prophets, his present-tense declaration that fulfills the law and the prophets.

Peter J. Leithart is President of Theopolis Institute.