Matthew 9:12-13

But when Jesus heard that, He said to them, “Those who are well do not need a physician, but those who are sick.  But go and learn what this means.  I desire mercy, and not sacrifice.  For I have not come to call the righteous, but sinners to repentance.”

At one point in our lives, we as Christians answered the call.  We were sick and didn’t even know it until we found the truth in God’s word.  Now, we are representatives on this earth for Jesus showing kindness and mercy to those who are sick and don’t know it.  By our example and in love, we can bring people to repentance.