Baptism for the dead, as performed by some religious groups today, is a non-biblical practice in which a living person is baptized in lieu of a person who has passed away. The purpose of baptism for the dead, or vicarious baptism, is to make a public profession of faith for a person who is already deceased. We can essentially think of it as the practice of baptizing a dead person.
The concept underlying baptism for the dead is that baptism is necessary for salvation, that those who have died un-baptized cannot inherit eternal life. Those souls need someone still living to become a surrogate for them; if someone will be baptized on their behalf, they may be granted access to heaven. But this contradicts Scripture. The notion that baptism merits salvation is itself unbiblical. Further, salvation is a personal matter—it cannot be conferred upon anyone based on the faith of someone else. The practice of baptism for the dead has nothing to commend it in Scripture.
What, then, do we make of 1 Corinthians 15:29? In that verse, in the middle of a discussion of physical resurrection, Paul says, “Now if there is no resurrection, what will those do who are baptized for the dead? If the dead are not raised at all, why are people baptized for them?” This is a difficult verse to interpret, but we know from the rest of Scripture that it does not mean a dead person can be saved by proxy. We can rule out the idea that the baptism of someone living can benefit someone dead. As already noted, baptism is not a requirement for salvation in the first place (see Ephesians 2:8; Romans 3:28; 4:3; 6:3–4). The entire passage of 1 Corinthians 15:12–29 is about the surety of the resurrection; “baptism for the dead” is only mentioned in passing to bolster the truth that the resurrection is our confident hope.
There have been many different interpretations put forward to explain what 1 Corinthians 15:29 means in referring to those “who are baptized for the dead.” Some believe Paul is referring to a pagan custom or to a superstitious and unscriptural practice in the Corinthian church. But why would Paul, a champion of salvation by grace, countenance such a practice?
Here are three viable interpretations that preserve the doctrine of salvation by grace through faith:
1. Those baptized for the dead “had been baptized with the hope and expectation of a resurrection of the dead. They had received this as one of the leading doctrines of the gospel when they were baptized. It was a part of their full and firm belief that the dead would rise” (Barnes, A., Notes on the Bible, 1834). According to this view, the verse could be paraphrased like so: “Every Christian has embraced belief in the physical resurrection of the dead, a doctrine illustrated in the very act of baptism. To deny the resurrection is to denounce the very foundation of the Christian faith and make baptism meaningless.”
2. Those baptized for the dead are those who are taking the physical place left vacant by believers who have already died. The idea of 1 Corinthians 15:29 is that, as Christians are martyred, their places are continually being filled by new converts, ready to take a stand for Christ. One commentator likens this to “ranks of soldiers that advance to the combat in the room of their companions who have just been slain in their sight” (The Works of the Rev. P. Doddridge, Vol. 9, Leeds, 1805, p. 99). C. I. Scofield paraphrased the verse this way: “Of what value is it for one to trust Christ and be baptized in the ranks left vacant by the believing dead, if there is no resurrection for believers? Why place life in jeopardy and forfeit the benefits of this life, if there is no life after death?” (The Scofield Study Bible III, NKJV, Oxford University Press, 2005, p. 1,593).
3. Those baptized for the dead are “living believers who give outward testimony to their faith in baptism by water because they were first drawn to Christ by the exemplary lives, faithful influence, and witness of believers who had subsequently died. Paul’s point is that if there is no resurrection and no life after death, then why are people coming to Christ to follow the hope of those who have died?” (MacArthur, J., The MacArthur Study Bible ESV, Crossway, 2010, p. 1,710).
The Mormon practice of baptism for the dead is unscriptural and traces back to Marcionism, a heresy of the mid-second century AD. The rite of baptism is a way for the living to proclaim their faith and commitment to Jesus Christ. It is not to merit grace or confer the hope of salvation upon the dead.