And the scribes of the Pharisees, when they saw that he was eating with sinners and tax collectors, said to his disciples, “Why does he eat with tax collectors and sinners?” And when Jesus heard it, he said to them, “Those who are well have no need of a physician, but those who are sick. I came not to call the righteous, but sinners.” Mark 2:15-17
Here is J. C. Ryle:
The Lord Jesus did not come into the world, as some suppose, to be nothing more than a law-giver, a king, a teacher, and an example. Had this been all the purpose of His coming, there would have been small comfort for man. Diet-regimens and rules of health are all very well for the convalescent, but not suitable to the man laboring under a mortal disease. A teacher and an example might be sufficient for an unfallen being like Adam in the garden of Eden. But fallen sinners like ourselves need healing first, before we can value rules.
The Lord Jesus came into the world to be a physician as well as a teacher. He knew the necessities of human nature. He saw us all sick of a mortal disease, stricken with the plague of sin, and dying daily. He pitied us, and came down to bring divine medicine for our relief. He came to give health and cure to the dying, to heal the broken hearted, and to offer strength to the weak. No sin-sick soul is too far gone for Him. It is His glory to heal and restore to life the most desperate cases. For unfailing skill, for unwearied tenderness, for long experience of man’s spiritual ailments, the great Physician of souls stands alone. There is none like Him.