Remember the character of Wilson in the movie Castaway? It seems to me that's exactly why the idea of "God" continues in this enlightened age. Ancient people may have initially invented gods to explain the universe and to have someone to blame for all the natural phenomena around them. But we don't need that anymore, since we have a pretty good understanding of science and nature. Perhaps God continues because we fear the existential feeling of "aloneness."
The Tom Hanks character in the movie endured a lot of pain and hardship and heartbreak. But the one thing that threatened to be the end of him was the loss of Wilson - and finally being totally alone.
Is that part and parcel of the human condition, then? Is extreme loneliness tantamount to death? Did we invent God as a kind of imaginary friend to help us through the life so that we never, ever have to feel totally alone?
Psychologically, then, it seems the idea of "God" can have some tangible benefits. If only the idea of God hadn't caused so much crazy hatred, violence and death in the world! If people were able to have their imaginary "gods" without hurting others, and without being compelled to convince others to accept their version of Wilson, then I'd have no problem with it.
Personally, I find myself (figuratively) crying out, "Wil-l-l-l-l...... son-n-n-n-n-n-n" as I sadly watch my beaten and battered volleyball float away and disappear on the ocean swells. It's sad to lose a friend, however imaginary the friend was. Goodbye, God.
Lucky for me though, I'm not lonely in my life. Thank Wilson.