Will a sign from God will convince us of his existence?

[Esquilax]

Okay try this one...suppose the name Jesus was found inscribed on the cell walls of a bacteria presumed to have been present since the dawn of creation...

Well, that'd lead to some interesting experiments, I'd bet. For example, we could search for the genes that cause that bacteria to manifest the writing, see what those are for. We'd have to know if all iterations of this bacteria sport the same writing, or if it was just a single mutation. Lots of things.

Honestly, the perspective of most of the atheists here, I would bet, would be that one should rigorously interrogate any claim one comes across for veracity, especially when it comes to scientific claims. Why do you think that having the same response when it comes to supposedly miraculous or divine claims is somehow dishonest?

Oh, and incidentally, would the word "Jesus" be written in english, or some other language? English would be kind of a weird choice, given that Jesus himself never spoke it.