In your opinion what causes christians to believe in Jesus

[Paleophyte]

The problem with sourceless-light is that it will kill you and it'll do it very quickly.

We survive our sun because it's a finite source that occupies a relatively small chunk of the sky. Light comes in, light goes out, and everything cooks along a smidge above the freezing point of water.

By contrast, sourceless light would come from everywhere and wouldn't be able to go anywhere. Well, not until enough of it accumulated anyway. It would come in and pile up in big drifts. Energy in, no energy out. That would stop once we got hot enough to re-radiate the light, which would happen faster than you might expect. That involves heating the Earth up enough to make it glow like a star though, and that'll have unfortunate side-effects.

But please, continue this hilarious attempt at marrying Bronze Age myth and modern science.

Sounds a bit laser-ish, minus the coherent light.
I don't wanna live inside a laser

More of an EZ-Bake oven cooking along at sun surface temperatures, so you wouldn't have to worry about living for very long.