I would also like to say something.
Someone growing their leg back isn't necessarily proof God exists. It's a Miracle, right? Yes.
Now, it gets proved by science. Person X had Condition and Gene Y, which combined with Z factor makes it possible. Is it not a Miracle anymore?
So, now that its proved by science, that clearly means that any God could have zero involvement.
Because, if God made the Universe and everything else, 'Science' is its own thing, and happens without any involvement whatsoever.
You live. There is a world around you. There is a whole fucking universe, of animals, humans, conversation, music, pizza, horticulture. Something exists. Why is there anything at all? God is an easy answer here too, but then again, you ask yourself about God, and whether he exists.
And at the point where you realise that nothing makes sense (or at least, one of these points depending on how easily you get confused) you might start to think about the possibility.
Or at least, that is how I started actually thinking about it, and believing it.