Look at any arab country. (Except for UAE). Then look at Norway, Sweden Finland, who aren't as religious. Even the U.S isn't radically religious. The only bad secular country in the world right now would be North Korea, but there a special "case".
Iran, Saudi Arabia and other middle eastern countries are corrupted and third-world countries. South Korea and Japan on the other hand are developed and rich and they tend to be more secular.
It's pretty obvious that the secular countries are doing much better for themselves. However that's most likely because people living in poorer, less hospitable countries turn to religion to feel good about themselves even though they live in a pretty bad place.
Sweden, the Czech Republic, Japan...
Generally secular countries tend to be more open to scientific discoveries while religious nations tend to repress large groups of people. Religious nations also tend force people into roles based on their teachings instead of giving them the freedom to do what their good at.
History shows this to be true
America is founded on Christian principles.
It doesn't really matter that much. I just picked this one for notifications.
Is there a correlation between the fact that as religion is pushed out of popularity in the US that our prosperity also happens to be trending down? Maybe theyre related? Who knows.
The rise of Christian faith has been related to nation's prosperity historically. First, Europe with its Christian belief built an empire (abused the power though), then the United States, with its Christian principles at its beginning. Then China, which although it bans Christianity and any other religion, still has many underground believers and is experiencing a rise in Christianity. When Christianity declines, the nation does the same. Look at what happened to Europe in the last few decades: now it is struggling to keep itself from defaulting (except maybe Germany).