Q: What evidence do we have of Jesus' resurrection? Please don’t use the Bible.
A: Um...I'm not allowed to use the eyewitness testimony? Okay, I...um...huh. What kind of evidence is possible, if eyewitness testimony doesn't count? I'm guessing you won't accept second-hand information, either.
I mean, replace "Jesus' resurrection" with any other event that took place 2000 years ago, like Julius Caesar's death or Cleopatra's visit to Rome. Really, our only proof that it happened is "people wrote about it afterwards". And even then, you can be skeptical and say they were lying. In fact, I would not be surprised if the people who wrote about Cleopatra were lying.
If eyewitness testimony and textual evidence are disregarded, I'm not sure what sort of evidence is left. Fr. Robert Barron made a video about this recently, so maybe he has some good ideas.
Hm. He's saying that Jesus rising from the dead wasn't a scam made up by the apostles, because they were 100% convinced it was true. Jesus' resurrection immediately became the center and focus of their lives, to the point that they were willing to die in brutal, horrific ways as a testimony to it. They would not have shown such dedication, if it was all something they made up.
I've also seen the argument that the story of Jesus' resurrection would be completely different, if it was a scam. After all, scams try to seem as legitimate and believable as possible. This is not the case with Jesus' resurrection; all the sources agree that the first person to see Jesus after his resurrection was Mary Magdalene. Her testimony was so unreliable that the first person to call her a liar was Saint Peter, AKA the first Pope, AKA the man who holds the keys to the gates of Heaven.
If it was all a scam, why on Earth would it start with the least reliable witness? In the first century, even a slave's testimony would be considered more reliable than a woman's. The only good reason to start with Mary Magdalene's testimony is if it really happened. If Saint Peter was making it all up, why would he publicly spread this (and many other stories) that makes him look bad? (This goes for every story in the New Testament; the majority of them present the apostles as selfish, liars, idiots and traitors. Seems unlikely that they would fabricate such stories about themselves.)
Another argument I've seen is that Jesus performed many, well-documented miracles prior to the resurrection. This argument was more convincing to people at the time, who witnessed the miracles.