What is the function of religion?

[Ryantology]

Well, I think the only point you are really right about is that religious dogmi tends to make people ignorant about science, at least to the extent it is opposed to these dogmi, and that some religious moral codes (e.g. concerning homosexuality) are out-dated. Sure, I fully agree.

But on the other hand ... I have read about results which claim that religious people are, on average happier and have less problems with drugs, have smaller divorce rate etc, compared to non-religous folks.

It's easier to be happy and live on the straight and narrow when you belong to the dominant belief system. Belonging to a minority religious belief is apt to subject you to a lot of extra stress, if not outright abuse and persecution. So, yeah, not being a persecuted minority will probably lead to you being happier. That doesn't suggest that the majority belief system is useful in any way, just that it is good at keeping everybody else down.

And in the West religious people produce more children ... The population growth is a huge problem in the IIIrd world, and religion plays here a crucial role, but on the other hand, in the West, the birth rates of purely secular people are dangerously low.

Population growth is a huge problem, precisely because there are too many people.

But, just because you're born into a family that is religious is no guarantee that you'll stay in that religion later, especially in a looser environment. Most of us atheists didn't come from atheist parents. I sure didn't. They have to reproduce at higher rates just to keep up, because the old-school style of converting people isn't doing the trick anymore. The market share, and even moreso, the influence of Christianity everywhere in the developed world is on the retreat. The fact that I can say this on a public forum without fearing retribution is proof of that.

A fact: on this planet, no society has ever attempted to exist without a religion (or a leader-worship system which was functionally identical to a religion). Let's actually try the experiment before we declare it a failure.

Sure. but am I incorrect if a maintain that one should have proper understanding of religion so that, in getting rid of it, one does not throw a child away with the washing water? I am NOT claiming that you couldn't have all the benefits of religion without the bullshit, but I am less certain how our current hegemonic secularism accomplishes this task.

What benefit does religion actually have? Historically, religion has not tried to supplement society, but rather has tried to conquer and define society. What practical need do we have for religion that a technologically-advanced society can't better serve in other ways? I honestly can't think of any.