The sheep in this parable already belongs to the flock; it has wandered. Jesus tells the story right after warning, 10"See that you do not despise one of these little ones," ordinary believers who have started to drift, and the shepherd's answer to drifting is a search. He leaves ninety-nine safe sheep on the mountains to go after the one that is missing, and when he finds it, Jesus says, the joy over that one outweighs the comfort of the ninety-nine who never wandered. Love feels its depth most sharply when something it loves was nearly lost.
Then the sentence at the hinge of the whole passage. 14"It is not the will of my Father who is in heaven that one of these little ones should perish." Everything Jesus says next about confronting a sinning brother has to be read in that light. It is the same shepherd's heart, handed to the whole church to carry out.
15"If your brother sins against you, go and tell him his fault, between you and him alone." The first move is private, quiet, and direct, so that shame is not piled on a wandering brother before it is needed. The verse ends on 15"you have gained your brother." The word "gained" is the whole point stated plainly. The goal was always to get the sheep back.
Only if that private appeal fails does the circle widen, first to two or three witnesses and then to the whole church. Only after every one of those steps has been truly tried does Jesus describe the hardest outcome, that the person be to you 17"as a Gentile and a tax collector." Even that outcome leaves room for pursuit, because Jesus himself was famous for pursuing exactly the people that phrase names, Gentiles and tax collectors, written off by everyone else as beyond reach. The door closing on fellowship was never meant to close the door on hope.
The process is shared. One person confronts privately. If that fails, others are brought in. If that fails, the gathered church takes it up. That is built-in protection against solitary judgment, one person's private certainty, however sincere, tested and steadied by others instead of trusted on its own. Jesus grounds that work in prayer: 19"if two of you agree on earth about anything they ask, it will be done for them by my Father in heaven." And he promises his own presence right here, in this hard work. 20"Where two or three are gathered in my name, there am I among them." That promise is attached to the difficult, patient work of trying to win back a brother.
Discipline done this way is the shepherd's search carried out by human hands, across four widening circles of appeal, refusing at every stage to let a wandering brother drift out of sight. It is the opposite of shunning.
Think of someone who has drifted. Before you say anything to anyone else, go to them alone, and go to gain them back.
Prayer
Father, thank you that you have never treated our wandering as an acceptable loss, that you leave what is safe to come looking for what has strayed. Give us that posture toward the people in our lives who have drifted, patient enough to go privately first and honest enough to keep pursuing instead of writing someone off. Thank you for your presence promised in exactly this hard, patient work. In Jesus' name, amen.