If ancient people met a modern human, what are some things they could/would use as inspiration for a religion?
Sounds like a crazy question, but there's a reason: I'm currently developing the story for a feature film where the protagonist wakes up in an alternate universe in which he is worshipped like a God. There is an entire established, centuries-old religion dedicated to his mythos. There's holidays, tenets, rituals, etc. all focused around this one guy's existence.
The problem is I'm having trouble figuring out exactly how those things should all develop. He goes back in time and interactions with either late BC or early AD humans (they obviously can't understand him), but I can't see how this would develop into the specific religious practices of the present alternate-future.
It's difficult because I’m trying to figure out a couple of things with the world building here:
The religion's core beliefs (at least common ones among the denominations)
Rituals
Fashion/hair
Rituals + holidays
If anyone has any ideas based on real examples of small facets of society that became important pieces of religion or just using your imagination, I'd greatly appreciate it. Just not sure how to approach this.