As I was reading through Jonathan Edwards Notes on Scripture I found this interesting interpretation of 1 Corinthians 15:29:
Else what shall they do which are baptized for the dead, if the dead rise not at all? Why are they then baptized for the dead?” What folly is it to baptize for persons that are dead and not risen again, nor ever to rise! What folly is it to baptize in the name of such! But this is our case, if there is no resurrection of the dead; we are baptized in the name of a dead Man. But who are we if He is not risen, nor to rise? [So] the foregoing verses, speaking of the resurrection of Christ, as from the 16th verse, “For if the dead do not rise then is not Christ raised: and if Christ be not raised, your faith is vain; ye are yet in your sins.” And if so, surely our baptism is also vain, as in this verse; and why stand we in jeopardy every hour, if Christ is yet dead and so to continue.
This is perhaps the most convincing interpretation of one of the most difficult passages in Scripture. The one objection I have heard to this interpretation is that the Greek word for “dead” is used in the plural in the verse, “Why then are they baptized for the ‘dead.'” The argument against this interpretation is that Christ could not be meant since Paul uses the plural form of the word ‘dead.’ But Edwards shows that the section begins with Paul’s statement in verse 16, ‘For if the ‘dead’ do not rise then Christ is not raised.” There the plural is used and Christ is categorically in view. So it is not a stretch to see Paul picking up on what he began in verse 16 again in verse 29. When he says, ‘Why the are they baptized for the dead,” he means to say ‘Why then are they baptized in the name (on account of) a dead Christ.
Jonathan Edwards Notes on Scripture (New Haven: Yale University Press, 1998) p. 53