What would need to happen for you to be able to distguish between a God and more advanced technology.
There's an important difference between belief and worship at play here. If I saw a god appear in the sky, and so did everyone else, and there were no other logical explanation, then I would accept that this god existed. If this god were anything like the God of the Bible or the Qur'an, then that God does not deserve to be worshiped.
When he knocks on my door & when I open it, he gives me the things I prayed for when I was religious. He would also give me the things I chanted for when I was a Buddhist. He would apologize for taking so long to get to me & he would actually show me heaven without me having to believe, have faith or be dead. Then he would bring me home here in Montana & we would have a discussion about the important things he has done nothing to help; the environment, overpopulation, christians who would kill women for having an abortion or kill gay people just for being gay. He would eliminate all those types of idiots. I could go on but I think you get my drift.
We live in the Milky Way galaxy. It has 1 billion stars. There are millions of galaxies. I can't believe the God of the universe wrote a book for us to live by. We are only one little planet. The biomass of bacteria on earth is many, many times more than the biomass of humans. The idea that we have a personal relationship with a God is only a manifestation of our ego.