John 21:16

16.Feed my sheep. Christ does not give to Peter and others the office of feeding all sorts of persons, but only his sheep or his lambs. He elsewhere describes who they are whom he reckons to belong to his flock.

My sheep, says he, hear my voice, and follow me; they hear not the voice of a stranger,
(John 10:5.)

True, faithful teachers ought to endeavor to gather all to Christ; and as they cannot distinguish between sheep and wild beasts, they ought to try by all methods if they can tame those who resemble wolves rather than sheep. But after having put forth their utmost efforts, their labor will be of no avail to any but the elect sheep; for docility and faith arise from this, that the heavenly Father delivers to his Son, that they may obey him, those whom he elected before the creation of the world. Again, we are taught by this passage, that none can be fed to salvation by the doctrine of the Gospel but those who are mild and teachable; for it is not without reason that Christ compares his disciples to lambs and sheep; but it must also be observed, that the Spirit of God tames those who by nature were bears or lions.