ISB ~ 1 Corinthians 15 v29

baptized on their [the deads’] behalf:This passage continues to baffle interpreters, since neither the form nor the meaning of this practice is familiar to us today. Perhaps living believers were receiving baptism for the sake of deceased persons, hoping its benefits would accrue to them in the afterlife (cf. 2 Mac 12:39-45). Another possibility, suggested by the verses that follow (1 Cor 15:30-34), is that Paul is talking about people who endure a baptism of suffering for the sake of others who are physically or spiritually dead (Mk 10:38; Lk 12:50). Either way, Paul reasons that such baptisms are pointless apart from belief in

a future resurrection.