At one point during his talk the Karmapa stopped and considered whether being a Buddhist actually made him a good person.
“If someone were to ask me whether I consider myself a Buddhist, I would automatically say yes,” he explained. “But if someone asked the followup question whether I think I am a good person, I would not be able to answer on the spot. I think sometimes I am a good person, and sometimes I am not a good person. This is a contradiction. If I am sure I am Buddhist but not sure whether I am a good person, that is a bit funny!
“The point of Buddhist practice is to be a better person. If you are unsure whether you are a good person or not then your identification of yourself as a Buddhist is very questionable.”
~Karmapa Teaches on the Four Dharmas of Gampopa in New York