I’m not sure how I can answer this question in terms of a positive answer (ie: “If I see _____, then I accept that God exists.”), but I will accept God’s existence if someone gives me an argument and/or evidence that I can exam and/or pick apart.
Just to show you that I’m open-minded on the subject, Neil DeGrasse Tyson moderated a debate that seriously examined the question of whether or not the Universe is a computer simulation. There seems to be “error-correcting software” numbers when one examines the mathematics of string theory, and quarks seem to follow many of the same rules as a “byte” of computer information.
These arguments have much more credibility with me when discussing God than anything that a Creationist has given us so far. Please see below:
If I have to entertain the idea that the whole Universe is a computer simulation, then “Who built the computer?” becomes a legitimate question.
I can still think of scenarios where the computer has always existed . . . but I find the God hypothesis to be much, much more credible if, indeed, the Universe is a scenario running in a kind of cosmic video game.
So I am open-minded . . . just not so open-minded that my brains fall out.