1 Corinthians 15:29

What shall they do [τ ι π ο ι η σ ο υ σ ι ν]. What will they effect or accomplish. Not, What will they have recourse to? nor, How will it profit them? The reference is to the living who are baptized for the dead.

Baptized for the dead [β α π τ ι ζ ο μ ε ν ο ι υ π ε ρ τ ω ν ν ε κ ρ ω ν]. Concerning this expression, of which some thirty different explanations are given, it is best to admit frankly that we lack the facts for a decisive interpretation. None of the explanations proposed are free from objection. Paul is evidently alluding to a usage familiar to his readers; and the term employed was, as Godet remarks, in their vocabulary, a sort of technical phrase. A large number of both ancient and modern commentators 128 adopt the view that a living Christian was baptized for an unbaptized dead Christian. The Greek expositors regarded the words the dead as equivalent to the resurrection of the dead, and the baptism as a manifestation of belief in the doctrine of the resurrection. Godet adopts the explanation which refers baptism to martyrdom - the baptism of blood - and cites Luke 12:50, and Mark 10:38. In the absence of anything more satisfactory I adopt the explanation given above.