Is believing in God Useful?

Pragmatically speaking, it depends on the person. For some people believing in God just might make them commit suicide because of the overwhelming nature of God in one's life. Other people absolutely could not survive another day without believing in God.

For example, in my own case, because I had childhood blunt trauma epilepsy likely I would have killed myself without God to hold onto through all that terror and mayhem until I was 15. But, it also had to do with the era I grew up in. In the 1950s believing in God was pretty important and if you didn't your life could be easily ruined even in California if people found out you didn't believe in God. In other words you might not have had a future or someone might have even killed you if you were too obvious about being an atheist then. So, on about 1000 or more levels it was much easier for me to rightfully say, "I believe in God!" and "I'm a Christian" to people even though my beliefs might have been somewhat unique growing up as a mystical Christian to a lot of people. But, by keeping it simple with "I believe in God" and "I'm a Christian" it saved me a whole lot of times all sorts of hassles in my life then (even in California).

However now, I think it likely depends upon who you are around. Some places in the U.S. it is necessary to your survival to tell people you are a Christian on all levels. Other places like big cities in California people might not care at all. So, you can basically believe whatever you wanted to right now as long as you aren't harming or hurting anyone.

So, mostly now I would say believing in God is more about what you need to believe than anything else. People don't need to say they believe in God even if they don't anymore most places here in the U.S. However, if you are poor and starving and need someone to feed you don't go to a church and tell them you are an atheist and expect them to feed you because they might not.