On the 500 eyewitnesses claim, you leave out that Paul said some had fallen asleep (died) BUT the greater part of them are alive to this day, so people could easily fact check him.

Secondly, Paul is not the one making this claim. He said he passed down WHAT HE HIMSELF RECEIVED. It was an oral tradition that was already circulating soon after the resurrection allegedly happened. So many people were aware of this event and would likely have known who these 500 people were.

Third some of the eyewitnesses DID write down accounts. They are called the gospels! They are written by the apostles (and Luke) who were part of the people Jesus appeared to as per the tradition in 1 Corinthians 15. They might also have been part of the 500, we dont know...but to say we have no eyewitnesses outside Paul's claim is a bit weird.

Finally, you have to account for why Paul himself became a believer in Jesus and started preaching the resurrection after initially unaliving those who believed in the resurrection. Why the 360 turn? Paul himself tells you why in 1 Corinthians 15 "Jesus appeared to him also" and elsewhere he asks "Have I not seen the Lord?" (1 Corinthians 9).

My friend, please seriously consider and wrestle with the evidence before writing things like this dismissing it.