I don't know if anyone's said this yet, but I'll say it...
God's like the wind, you can't see him or the wind but you can see the effects around you (IE:The trees blowing in a certain direction, leaves blowing in that direction) ( IE. Miracles, Supernatural things happening) stuff like that
. If God didn't exist because we couldn't see him, then you don't have a brain because I don't see it...see where that goes, I hope that helps