what is finite pain to an infinite being?
Crucifixion was a terrible way to die, no question, and the tortures Jesus endured made it many times worse.
But then he got to rise again on the third day and went on to rule the universe for all eternity.
Compared to an eternity ruling the universe, a few hours' pain seems pretty trivial.
And PLEASE, before you start extolling the virtue of suffering unjustly because Jesus is the perfect being, remember that the "injustice" like the suffering itself pales in comparison to eternity ruling the universe.
Earlier myths included sacrificial martyrs like Prometheus, and the miraculously resurrected like Horus or Mithra. But combining the two seems to cancel out. Unless I'm missing something.