Christian baptism includes a testimony of our belief in Christ, but it refers chiefly to God and to what He does for believers. Baptism, Westminster Confession of Faith 28.6 tells us, actually confers divine grace, albeit only to those to whom the grace “belongs”—the elect. We know this to be the case since only the elect of God receive His saving, regenerating grace (Rom. 9:1–29) and since the New Testament speaks of baptism in ways that make it more than a visible depiction of spiritual realities. Something actually happens in baptism—grace is conferred—but only to the elect, who invariably respond to that grace with repentance and faith, though the time of response does not necessarily coincide with the time of baptism.
We will consider the timing of baptism and its effects more in a few days. Today we will look at how Scripture speaks of baptism as accomplishing what it signifies. Using today’s passage as a prooftext, Westminster Confession 28.1 speaks of baptism as the sign and seal of “ingrafting into Christ,” or union with Christ. According to Romans 6, our baptism buries us with Christ in His death. Paul does not say we are buried with Christ because we are baptized. No, we are joined to Christ in His burial because God elects us, regenerates us, and grants us faith (Eph. 1:3–6; 2:8–9). Still, as union with Christ is dependent on the grace of God exhibited and conferred to the elect in baptism, Paul can say our baptism buries us with Christ.
Admittedly, we cannot describe exactly how this happens. We cannot be united to Christ apart from personally trusting in Jesus (John 3:16; Rom. 4), so baptism in itself cannot unite us to Christ. Yet we cannot have faith without the gift of God’s saving grace, which is somehow conferred to the elect in baptism since baptism is a sign of that salvation. Ultimately, there is mystery here that must be preserved. We tend to err by collapsing the sign and the thing signified together such that baptism regenerates all who receive it, or by so divorcing the sign and the thing signified that baptism confers no spiritual benefit even to the elect.
Whether we are immersed, sprinkled, dipped, or receive a pouring, we come under water—are buried—in baptism. Thus, our union with Christ is signed and sealed . And if we are truly baptized into the death of Christ, we are also united to Him in His resurrection. Baptism is God’s promise to believers that our old Adamic selves have been crucified and that we are new, resurrected creations in Christ.