The Mishna in Pirkei Avos (4:1) says that a Chochom is a person who can learn something from everyone. When the Mishna says everyone it means it. The Magid of Mezritch (Yeina Shel Torah) says there are 7 things we can learn about Avodas Hashem from a Ganif, a thief.
1. He does his work at night, out of public view
2. He never gives up. If a plan fails the first time he will try again
3. He loves his accomplices and will protect them at all costs
4. Even a small heist is important in his eyes and he is willing to be Moser Nefesh for it
5. Whatever he steals with great effort he is ready to dump at a low price and does not place great importance in it
6. He does not discuss with anyone what he has done or what he plans to do
7. He treasures his profession and is not willing to trade it for anything else in the world
Another version in the name of Rav Zusha of Anipoli was submitted by a reader (Thank You!) goes as follows.
a) He works quietly without others knowing.
b) He is ready to place himself in danger.
c) The smallest detail is of great importance to him.
d) He labors with great toil.
f) He is confident and optimistic.
g) If he did not succeed the first time, he tries again and again