Religious devotion is expressed in different ways across the world. Humans fantasize in the way they worship their divine. They allocate all their energy and creativity in order to build exotic monuments, statues, icons, etc...
Other than the art of architecture which is different in every religion, they differentiate themselves in the way they design their clothing or do their haircuts.
What attracted me about the Sadhus, the Hindu holy men, is the way they paint their faces. This ritual is called Tilak which is the forehead, it is the place of the third eye or the eye of wisdom.
The paintings come in different shapes and color combinations to symbolize the deity they devoted themselves to.
At the end, I believe art & design are an essential part of the human evolution since the beginning of our time. It also plays a main role in how people worship their supreme power.