well art progresses in movements. so after the Roman era and Constantine became the emperor of Rome and made Christianity the central religion, then religious art was the only thing people really did because it controlled everything in society so deeply, but the artists where used to promote it, so thats why a lot of famous art and artists had a spiritual or religious take, like Michaelangelo, etc
but id look in whatever time period youre interested in an pull art from there. a lot of primitive and stone age art has cool tribal designs, gothic art, art nouveau. just learn about the different art movements, each one has key artists that may have something you find interesting but other than the christian art era most movements have artists who are spiritual, some who arent, etc.
im a nerd, I know lol
