If someone asks me whether I believe in God, i would probably ask them how do they define god.
If God means some entity which created this whole universe? Maybe. We might as well be a science project of some alien kid. Like we study ant colonies, maybe someone is studying us in their mason jar.
If God is an entity with all power Maybe. If it's able to create us, it might as well have power to control things. Things like weather, solar flares, maybe.
If God is all knowing and all good entity Probably no. I wouldn't call god a good being if it looks at humans killing their own planet and does nothing.
So what do we do with people who believe in such entity? For many of such people this belief is their support in difficult times. These beliefs don't come alone they also bring stories, traditions and festivals. These things are ingrained in our society. You can't imagine India without Holi, Diwali, it's local religious festivals. (So much productivity) Fortunately or unfortunately these religious festivals are a big reason for people to come together with their family, friends even coworker and just enjoy, forgetting about everything. Such gathering is very important especially in this digital age(I'm sounding like a prof who doesn't know shit) When everything is becoming online, these festivals are few of the reasons which gather people for good.
But what if we decouple religion from these festivals? Is that even possible? Even if we did, would these festivals still have the same effect?
Ok so this belief about God may not be bad, even though it might be factually incorrect. Then where does the problem lie? Problem arises when people start believing that only their belief is correct and whoever does not believe the same needs to be converted either by "educating" or by force.
The utopia for me won't be a place where no one celebrates religious festivals but rather a place where people accept that their belief might not be correct and still celebrate those festivals just cause it's fun.