Christians: Who are the people who are well, those who have no need for a physician?

I have a Life Application Study Bible and the explanation that it gives for this passage is: The Pharisees were constantly trying to trap Jesus. They used Jesus' association with "low lifes" as an opportunity to trap Him. Pharisees were considered themselves as "holier than anyone else - big time show -offs. Christians should not be part of that kind of show , but share the Good News with everyone regardless of their status in life as Jesus did.