Religion isn't really necessary. It's usually intertwined with culture. If you have a good culture, you don't really need religion. The Japanese are doing fairly well.
Discussion
I agree they are intertwined but I think they are different. Sweden and Italy are both historically Christian, but the culture is quite distinct. We can also compare Malaysia and Pakistan and we can see both Islamic countries are very distinct as well.
Up until our recent atheism Christian beliefs formed the basis of Western morality. Eradicating Christianity in the West has shifted Western culture dramatically. Degenerate behaviour and hedonism are now unchecked. What is to say what is “bad” or what is “good”? What anchors us?
Have you studied the history of the Catholic Church and its rule during the dark ages?
I understand your point. It is all too common for organised religion to be harmful or counter to society. The Catholic Church has a lot to answer for.
Human institutions are by their nature prone to terrible abuses. The point I am trying to make is that when an individual has a relationship with that which is above human institutions, a higher power, humanity is protected to some degree.
For example, let us say a random church promotes a genocide, but a Christian reading the Gospel realises that Christianity is about peace, love, caring, forgiveness, then that renegade church can be ignored.
There are moral truths that transcend time and space. These truths are not the product of governments or even a church. They derive from a higher power. If we lose that the descent into hedonism and tyranny cannot be avoided.