Why don't we know the date Jesus rose up from the dead?

[Thor]

Constantine wanted something that most, if not all, citizens of the Empire could find something to relate to. These stories were common at the time and it took little to integrate them into a whole.

I saw a program about Constantine on the History Channel not too long ago. According to the program, Constantine was heading into battle and one of his advisors (who was a Christian) told him that accepting Jesus would allow him to defeat his enemies. Not too long after this something crashed down from the sky (the program assumed it was a meteor). Constantine took this as a sign from "God" that he should accept Jesus. Constantine then converted to Christianity and had all his soldiers paint crosses on their shields. They even painted a picture of Jesus on some cloth and carried it into battle. Supposedly, this so unnerved Constantine's opponents that they fled. This, of course, inspired Constantine to declare Christianity as the official religion of the Roman Empire.

So.... if not for the happenstance of a meteor crashing, Christianity may very well not exist today. Or, perhaps, it would be a minor religion on par with Mormonism.