There was a huge iconoclastic controversy in the 7th or 8th centuries. I don't follow it well (I guess because my field is those very icons and graven images that were banned), but I think even images such as those of Justinian and Theodora would have been banned then too. So Early Christian art was not just flat because of the graven image ban (although sculpture was definitely a secondary art, perhaps in part because of the graven image idea).
I don't see the Frank Stella, the last image, as very spiritual; but he was explicitly inspired by those early Medieval pieces like the ones I posted, so that's why I included him. I do see, and feel, Kandinsky as very spiritual. His work just soars and raises my spirits (mood). But we dealt with him before.
A little off topic, but I've always considered Gothic Architecture to have been something of a peak in Christian Art.
Photographs don't usually manage to convey the feeling of spirituality that the architecture conveys when one is there in person. I say this as a not particularly religious person.
Anyhow, this photo of a crypt at Winchester Cathedral comes close.
![](http://www.winchester-cathedral.org.uk/images/gallery/crypt.jpg)