Okay, for a start, from the time of Jesus, we don’t have very many records. And the Byzantine empire didn’t exist until 300 years later, coincidentally when Christianity really took on. A good example is Pompeii. Basically all evidence we have for it is archaeological. There is only one written record which is written by a guy -surprise- who also mentions Jesus. The eruption of Mt Vesuvius was likely witnessed by around 250,000 people and killed many upper-class romans. In fact, the writings about Jesus are extraordinary as so many of them survived and exist in such a close timeframe to the existence of Jesus.
Secondly,
Because its got wizards and makes a lot of strong claims, including about wizards
Gonna assume by wizards you mean Jesus being God.
This is circular reasoning. “Jesus couldn’t have been God because there is no proof of Jesus being God, and the Bible isn’t proof because Jesus couldn’t have been God because there is no proof”
Basically you’re saying “Prove to me Jesus is God” “Okay, here’s your proof” “I reject your evidence because it claims Jesus is God when Jesus clearly isn’t God”
Thirdly, there’s archeological evidence of an early Church existing and early New Testament manuscripts from the second century. There’s even a stone tablet mentioning Pontius Pilate, which before it was discovered, critical atheists claimed was a fictional character.