Why are religious dogmas so utterly.... vague??

I am in the process of reading Pascal Boyer's "Religion Explained: The Evolutionary Origins of Religious Thought" and I came across something that I thought was rather interesting. He was discussing the nature of religious beliefs and said basically that for people involved in religious rituals they are not really concerned about the details of how their deity of choice operates...but they are certain that he does. 

This critique of religious concepts is interesting from a historical perspective. If you think about it every single aspect of human knowledge and inquiry has advanced light years in the past 2000 years. The various fields of science have allowed us to see and know things we never knew possible. Business and law and even ethics have all shown dramatic leaps forward. Contrast this to religion...where people still rely on the same texts, the same stories, the same messages and the same 'evidence'. There have been no new revelations. The messiah has not returned. 

You could ask someone if God answers prayers or if he miraculously intervened to save their lives somehow and they might say yes. However, if you ask them how exactly he did this, they are unlikely to give you much (if any) detail. 

"God works in mysterious ways". It's as if religious people are content with knowing the 'what' and 'where' but never the 'how'. How exactly is jesus christ going to return to earth? Will he come flying through the sky in a blaze of glory like superman? Or will he be reincarnated in the body of some illiterate, poor catholic man in some remote south american country somewhere?

I think this was one of the reasons I was always (in my pseudo-christian past) so incredibly unfulfilled and underwhelmed with religion in general. For someone with half a brain it really provides very little substance. It is absolutely remarkable that such a system is still taken seriously after 2,000 years. Especially considering that in modern society we depend so much on the details. From science to medicine to law to business we rely on highly complex and intricate details. Yet somehow this does not carry over into our religious beliefs. It is as though we willfully suspend our curiosity the moment we step into a church or open up a bible. It really is a pity.