According to Santayana, our primary reactions to great art should be but little dependent on non-aesthetic associations. The latter should be no more than the icing on the cake. Which is indeed usually the case.
But religious art is different. Religious art can be good even when almost our entire reaction to it is determined by non-aesthetic associations.
"Ann"'s image of the Dome of the Rock
Ann - Bait al-Makdis
has everything wrong with it. Images of real buildings, which are inherently three-dimensional and massive, usually do badly when turned into graphics. Geometric patterns mechanically repeated a few times on hang-on-the-wall-and-look-at-me art also tend not to work. They look mass produced. So does a pseudo-photographic rendering. And embossed foil posters produce in us an immediate kitsch reaction, for good reason.
Yet this image does work. It works because the image is simple and shiny enough to remind us of what it represents. And it reminds us of all of the niche and dome icons which preceded it in our history.
Religion is not mainly an aesthetic experience. It is an experience based on more primitive and direct emotions. Which is why religious art works even when it exploits our memories much more than our aesthetic sense.

I'm speaking of real religious art, of course, which is made to be used for religious purposes. I'm not talking about those cases where one paints a pretty girl in a pretty background and then stamps "Madonna and Child" on the box. In those cases the normal rules apply:  Beautiful is beautiful and so-what is so-what.
Raphael - La Belle Jardiniere Bouguereau - Mother and Child

Spaces, not commas, please!