Jesus is explaining to the Pharisees and scribes why He feasted with a group of outcasts and sinners. He cannot heal religious leaders who do not believe they need God's forgiveness. The Lord has come to save those who are aware that they are sinners and humble enough to repent of their sins. It is vital that local churches embody Jesus' statement. As Christians, we should expect and welcome sinners into our congregations.
It is important to note that Jesus ate and drank with sinners, as they were in need of salvation. The purpose of Jesus' mission was to save those who were lost in sin. In fact, he had not come to call the righteous in their own eyes but sinners to repentance. During Jesus' ministry, he came to save sinners who were aware of their sinfulness and recognized their need for salvation. 
Jesus came to save all men since all have sinned. The Bible states that all sinners, including cheating tax collectors and proud Pharisees, fall short of God's glory; therefore, Jesus came to save them all. Whether a Jew or a Gentile, rich or poor, black or white, old or young, a tax collector or a philanthropist, all need to be forgiven of their sins.

Dear Heavenly Father, many people in the world need Your healing hand upon their lives. Thank You for coming to heal the brokenhearted and free the captives from their bonds of sin. Throughout the day, I pray that many people will recognize the brokenness and sickness that has afflicted them and acknowledge the need for Your touch in their lives. Thank You for sending Christ to pay the terrible price for our sins and for healing us through His blood. 
In Jesus's name I pray. Amen.