In lieu of that, I would ask what you think would be adequate evidence to persuade you, personally, of God's existence? Hopefully you will not be silly but really think about this one. Still, if you want to be silly, go ahead, it's easier, and I won't really mind because this is only a small issue for me.
Also, I would question whether God (if he exists) is omnipotent. It might be entertained that God actually lacks free will, and can only do what he does do. The lion does usually not sit down with the lamb, nor a tiger change his stripes (except through evolution
)
In any case, humans do have free will. If God bludgeons people with overly dramatic and intrusive experiences and interventions in an effort to force his will on reluctant people, that would be cheating and constitute a violation of human free will by force, thereby defeating his own purpose of bring people to the light by means involving choice, love and healing benefits.
Note: I am not a proponent of God, religion, or any particular interpretation of the complex events at Fatima. That the events occurred is beyond dispute and people can and should educate themselves about it. I would be happy to cite important sources, as there are zillions, mostly poorish, out there.
In modest advocacy,
Dotini