John Calvin Commentary Matthew 18:11

"[For the Son of man came to save that which was lost.]" — Matthew 18:11 (ASV)

For the Son of Man comes. Christ now employs his own example in persuading his disciples to honor even weak and despised fellow believers; for he came down from heaven to save not only them, but even the dead who were lost.

It is completely unreasonable that we should disdainfully reject those whom the Son of God has so highly esteemed.

And even if the weak struggle with imperfections that may expose them to contempt, our pride is not excused for that reason. For we should esteem them not for the value of their virtues, but for the sake of Christ. And anyone who does not conform himself to Christ’s example is too insolent and proud.