Why do countries in the middle east allow religion to have such an influence?

[dyresand]

Yes, I understand this is the case here in the U.S. However, it is not extreme, we are at least a secular society. Now why is it those nations such as Iran, Saudi Arabia and many others allow Islam to have such a heavy influence and basically control their government and everyone that lives within it. Essentially, why is it hundreds of nations all over the world have become more secular, meanwhile the majority of the Middle East hangs on to Islam. Same with parts of Africa as well, however I am more interested in the middle east when it comes to this topic.

Extreme poverty = more religious. 
Because the poor tend to favor god and religion.
If on the other hand, the trend of mass poverty were to end maybe just maybe the world would get more secular.
But as it stands currently the wealth inequality is a worldwide problem hence forth the world turning more religious.