en_tn_condensed/1co/15/13.md

if there is no resurrection of the dead, then not even Christ has been raised

Paul uses this statement to argue that there is a resurrection of the dead. He knows that Christ has been raised and so infers that all who die will be resurrected. To say that there is no resurrection is to say that Christ has not been raised, but this is false because Paul has seen the resurrected Christ (1 Corinthians 15:8). (See: rc://en/ta/man/jit/figs-hypo)

not even Christ has been raised

This can be translated in active form. Alternate translation: "God has not raised even Christ" (See: rc://en/ta/man/jit/figs-activepassive)