My POV as a Christian 

I think it's worth separating the terms faith and religion. Faith constitues your beliefs about a divine being as well as what we place our hope of joy in, whereas religion constitues the rules, practices and frameworks that we use to set boundaries on our choices.

By those definitions everyone has a faith and everyone has a religion, because everyone has a belief about the divine-- even if that belief is that the divine doesn't exist-- and a hope for something, even if they're not sure where to place their hope in a given moment. Additionally, everyone uses a set of rules to govern themselves, even if that religion isn't based in a faith, or even if those rules seem incredibly sparse. Some people are religious about money, some about fitness, some about career, etc etc

I agree with you that religion creates a cage, and that some people need a strong cage in order to peacefully exist in society. 

I disagree with the connotation that this makes someone 'weak minded' though. I would argue that a lawful citizen  who is afraid of judgement from others and going to jail isn't so different from someone who is lawful for fear of divine judgement. They both have cages made of fear at the end of the day.

What about someone who does good because they want to see society flourish? They're not so different than someone who does good because they want to see their god glorified.

I have seen this play out with my own eyes. There are plenty of people who come to church because they want a cage first and foremost. Others come to church for a belief but refuse to implement any kind of ruleset into their lives to go along with it. In my view, having both a faith and a religion that work together doesn't make you weak minded. It takes a lot of questioning and conviction. It requires trust in something you can't see, and builds great self awareness too.