The question is on 1 Corinthians 15:29. Paul speaks about baptism for the dead as if it is an accepted practice in the early Christian church. To what he is referring?
The passage of scripture you are referring to is the following verse:
Otherwise, what will those do who are baptized for the dead? If the dead are not raised at all, why then are they baptized for them? (NASB) 1 Cor. 15:29
This is a difficult passage to understand because the concept of being baptized for the dead occurs only in this passage. When we encounter a verse or verses that seem to introduce a new idea that does not occur in any other place in the Bible, then we must be careful about our conclusions. We cannot develop doctrine from only one passage in the Bible. This is an important principle to remember.
What is the meaning of the phrase “baptized for the dead”? Is the answer found among the forty different interpretations of this passage that have been considered by preachers and teachers since the early church fathers? Here are a few of the major meanings that have been given to this phrase.
First, some have said the Corinthians believed that there was spiritual benefit (or efficacy) in being baptized. They have referred to 2 Macaabees 12:3-4 which tells us that the Israelites believed there was a benefit in praying for the dead. The Roman Catholic church believes this also.
And when he had made a gathering throughout the company to the sum of two thousand drachms of silver, he sent it to Jerusalem to offer a sin offering, doing there by very well and honestly, in that he was mindful of the resurrection: For if he had not hoped that those who were slain should have risen again, it would have been superfluous and vain to pray for the dead. 2 Macaabees 12:43-44
Did the Corinthians believe that prayer and baptism had spiritual benefits for the dead? Neither history nor archaeology tell us.
Second, others believe that the Corinthian Christians were actually being baptized for dead people. History tells us that some early Christians named Marcionites were doing this. But again, neither history nor archaeology tell us that really happened in Corinth. Today, the Mormons practice this ritual believing that they are saving those who died in unbelief.
It does not appear that the Corinthians’ conduct troubled the Apostle Paul since he never condemned the practice. Just twenty-nine verses earlier, Paul had taught that the only way to be forgiven was by trusting in Jesus Christ. So their practice was not about salvation for the dead or he would have rebuked them just as he did the Galatians in Gal. 1:6-9. We do not know why they were following the practice of baptism for the dead. That information has been lost to the passage of time.
Paul is not really interested in their practice. He only introduces their custom to support his message. The dead do live again! His conclusion is excellent. If the dead do not receive their bodies back again, why are you practicing this custom of baptism for the dead? It accomplishes nothing! The truth is this. Everyone lives forever (Matt. 25:46) and we all receive resurrected bodies at the end of the world (Rev. 20:4-5, 11-15). God is looking forward to living with those who before they die are trusting the Father to forgive their sins because of Jesus’ death and return to life. God wants to live with us! That is awesome.