An excerpt from Matt Wagner's panel from WizardWorld Chicago:
Talking about Jason Todd coming back as the Red Hood, Wagner wondered why there are Christians in the DC Universe since there are so many people that come back from the dead, rendering Jesus' resurrection as not out of the ordinary.
This of course is a very valid point. So Jesus Christ came back from the dead two thousand years ago. Superman did that 5 years ago, Donna Troy does it every month, and even the Green Arrow came back from the dead once. Resurrection should have lost its currency by now.
The problem of course is worse over in the Marvel Universe, where half the population has at one point died and come back to life (some Thanos crossover bru-haha) in the 90s.