Learning by modeling (as in the example of Francis of Assisi) is by far one of the most underestimated teaching methods of all. Perhaps it is because the technique is subtle, but the principle is foundational. It is easier to get students to think and do something that has been modeled than it is to get them to respond to something you are trying to market. instead of saying "This week we should try to reach out and share our faith in Christ with a stranger," we ought to just do it and talk about the experience as it is a reality, not just a good idea. If you want to teach students about forgiveness, get a few to quietly practice it, then share their experiences.