The article states that a lot of people in academia (Proffesors, Grad students or who ever else gets published in academic journals on the subject) start from the premise or believe that with rises in education and income comes a decline in religiosity. So getting rich and educated makes you less religious (as a society), which doesn’t sound entirely unlikely (to me at least). There is however no empirical evidence for this claim. Appearantly even college proffesors seem to be just as religious as other folk (with the exception of proffesors in the social sciences).
IIRC the amount of religiosity in highly educated professionals tends to depend on their field. With biologists leaning heavily atheistic and engineers tending to be quite religious.
Is there any evidence whether the correlation involves causation in one direction or the other?
This. You’d be hard-pressed to come up with noisier examples if you tried. The differences between the modern US and the US of the 1790s are so many that it would be impossible to do more than guess at the effect of education on religion.
When you do the study properly, by looking at a single society and controlling for other demographic factors, I believe you generally see a negative correlation (although not a particularly strong one) between education and religious belief.
What a moronic OP- and if it’s representative of God is Back, what a moronic book.
In fairness, if Christianity was the only religion, it would make perfect sense.
If an engineer screws up, people can die horribly. Maybe they figure a little prayer couldn’t hurt? 
It does seem to be the case around the world that the more and longer industrialized a country is, the less religious it becomes. The trend is visible even in the U.S.
This thread was bumped by a spammer, but I’ll leave it open.
Not that I know of. The most reasonable explanation that I’ve heard is that engineering deals with matters that most modern religious groups don’t try to dispute anymore. So someone highly religious who is intelligent and technically inclined can become an engineer and have a career that will never challenge his beliefs.
Religion is education, just different teachings then secular/standard schooling. Therefore the OP doesn’t make much sense, unless you state that as one type of education grows the other shrinks, which sort of makes sense.
This I differentiate with a personal relationship with God, which is spiritual, not religious, in conventional context. Spiritual people are usually very non-religious.
This might be the first time you’ve ever acknowleged that such people exist. 
This is quite true. Historically in Western Europe, the Catholic Church was the educational authority in town. If you wanted to learn to read and write, you had to curry favor with the church such as expressing interest in joining a monastery or by becoming a priest. In fact, reading and writing was, for a time, largely concentrated among monastics and priests. Very few others, even the rich, could read or write. This survives in the English language with the word “clerk”. Originally, it meant a priest or monastic person. Later, because those people were generally the only people who could read and write, it became a world meaning someone who can read or write, regardless of whether or not they held a position in the Church. Later, we re-imported the word from Latin as “cleric” and assigned it something closer to the original definition of “clerk”.
In more recent times, the Jehovah’s Witnesses religion has been heavily involved with basic literacy education in many areas of the world (no, I do not follow them, I’m just stating a fact).
A variant I once read (in National Geographic or one of its books, I believe) of Henry II’s famous “Will no one rid me of this turbulent priest?” is “Are there no caitiffs at my table who will rid me of this baseborn clerk?”