Many years ago, doing undergrad studies at the University of Miami, covering the period in the shift between what we now call B.C. and A.D., my history professor referenced one Jesus of Nazareth.
Speaking of his death on a Roman cross, he then went on to speak of his Apostles, who went out a short time later, and eventually far around the known world, proclaiming the message that Jesus had risen.
This aspect of the lecture didn't go over very well, as a few students protested loudly that we were attending a non-sectarian institution, and that religion should not be injected into a course on World History!
It was then that the professor indicated that, in fact, he was teaching history, not religion. He said people didn't have to believe anything the Apostles preached. But the fact that they actually preached it could not be reasonably doubted. It was an historical certainty.
Naturally, further investigation into the non-Christian writings of the time, from Josephus, Tacitus, and others, clearly shows that, indeed, there was a Jesus of Nazareth, crucified under Pontius Pilate, very soon preached as resurrected, by those willing to risk and expend their own lives to share this consistent and unusual message. Yes, that is history, requiring no faith.
Here's a quote from the Jewish/Roman historian Josephus:
"And when Pilate, at the suggestion of the principal men amongst us, had condemned him to the cross, those that loved him at the first did not forsake him; for he appeared to them alive again the third day; as the divine prophets had foretold these and ten thousand other wonderful things concerning him. And the tribe of Christians, so named from him, are not extinct at this day."
It's amusing to hear attempted "rational", non-faith based, explanations for the Apostles' known witness to the wider community -- extending from Ethiopia to India. Actually, it's very informative to draw these so-called "rational" explanations out to their logical conclusions, seeing if they are consistent with basic common sense.
Doing that, one is then left to seriously re-encounter and wonder if the "orthodox" account of Jesus is also the "historical" one.
Yes, Jesus was crucified. Yes, even to their known enemies, his disciples said he had been raised, and preached forgiveness in his name.
Why did they do this?
Well, it just may be that, as they said, on the first day of the week, the Tomb was empty and they personally encountered their Risen Lord in the flesh.
Thus, in the dramatic transition from what the Apostles were, to what we know they became, the discerning viewer can really see the Resurrection.