The faith I am talking about is not giving up on a piece when you are about 2/3 done. With about half of the art quilts I work on, I reach a point where I am sure that it's not worthwhile enough to finish. I am certain the concept is pedestrian and the execution haphazard. I have persevered sometimes only because I am too cheap by nature to see the fabric go to waste!
Most of the time, though, when I actually do finish the piece, it is somehow transformed. I can see clearly the thoughts and emotions I wanted to express when I started and, while I have never made a mistake-free piece, it has somehow come together.
Faith is believing that the work you do is worthwhile, that the effort to put your visions into concrete form produces art that communicates those visions to others. Like a lot of other things in life, halfway through it can look not only unfinished but impossible-to-be-finished. The peaceful, settled feeling you get when a piece is finally done is the proof that perseverance powered by faith is often the right, if not the only, choice.