On the Touchstone web site, there’s an article by Logan Paul Gage, “Staying Power”, that is an interesting current example of the argument that religion is socially beneficial. Presumably this means that religion deserves public support of some kind.
Some of the article is basic conservative spin. But it’s not entirely so easy to dismiss. The social science research Gage mentions is quite mainstream, as far as I can make it. There is real (if ambiguous) evidence that religiosity is associated with all sorts of things that may be good for human communities.
Now, all this is irrelevant to arguments concerning the truth of supernatural claims. We may even suspect that when defenders of religion resort to saying that religion should be supported for secular reasons, that is a sign that the gods are not as plausible as they once seemed. There’s a difference between saying that you should believe in Jesus because God commands it and this will save your soul, and saying that we should believe because it helps the crime rate or our blood pressure.
I should add that secularizing trends also need not mean much. Gage points to research by Robert Wuthnow to support his position, but Wuthnow’s “Myths About American Religion” seems to indicate a slight secular trend in the US, if anything. But this appears to be connected to intellectually irrelevant considerations such as people marrying and having children later in life. This sort of thing is common in social scientific explanations of religion in general. If people become more religiously indifferent, this typically has nothing to do with increasing awareness of science or spreading Enlightenment attitudes or anything like that.