Although my limited understanding of the history of this movement is that it is of Christian origin, certainly the shawls are not limited to those followers. My interpretation is that anyone who wishes to can knit, crochet, weave or otherwise create a comforting blanket of fiber while instilling his or her positive prayers, thoughts and/or energy. As an artist, I believe strongly that a bit of the energy and intention of the creator of any piece of art lives within that piece forevermore.
I'm now on my third shawl, having sent the first to a friend who is fighting cancer. It was knit in Homespun "Quartz."
It looked exactly like the one of the cover of this first book. I have been using Lion Brand Homespun yarn which knits up into a soft and cuddly shawl and, by the way, comes in no less than 66 colors. If you are interested in taking up needle or hook, here are the books I recommend as a start.