Here are some interesting videos about the Saw films. He describes Jigsaw's morality as an extremist Christian morality. "Perhaps watching the saw movies is like going to church". The videos talk about other parallels with Christianity, such as confession and doing penance. Very interesting stuff. Makes me want to go back and re-watch all the saw movies with this new perspective in mind.
Also the idea of using suffering as a means to become more ethical is very interesting. Stoic philosophy, for example, encourages voluntary discomfort. However, Jigsaw takes it to the extreme.
Philosophy of Saw
Philosophy of Jigsaw