Verily, verily, I say unto you, He that enters not by the door into the sheepfold, but climbs up some other way, the same is a thief and a robber.
All Commentaries on John 10:1 Go To John 10
John Chrysostom
AD 407
Observe the marks of a robber; first, that he does not enter openly; secondly, not according to the Scriptures, for this is the, not by the door. Here also He referrs to those who had been before, and to those who should be after Him, Antichrist and the false Christs, Judas and Theudas, and whatever others there have been of the same kind. And with good cause He calls the Scriptures a door, for they bring us to God, and open to us the knowledge of God, they make the sheep, they guard them, and suffer not the wolves to come in after them. For Scripture, like some sure door, bars the passage against the heretics, placing us in a state of safety as to all that we desire, and not allowing us to wander; and if we undo it not, we shall not easily be conquered by our foes. By it we can know all, both those who are, and those who are not, shepherds. But what is into the fold? It refers to the sheep, and the care of them. For he that uses not the Scriptures, but climbs up some other way, that is, who cuts out for himself another and an unusual way, the same is a thief. Do you see from this too that Christ agrees with the Father, in that He brings forward the Scriptures? On which account also He said to the Jews, Search the Scriptures John 5:39; and brought forward Moses, and called him and all the Prophets witnesses, for all, says He, who hear the Prophets shall come to Me; and, Had ye believed Moses, you would have believed Me. But here He has put the same thing metaphorically. And by saying, climbs up some other way, He alluded to the Scribes, because they taught for commandments the doctrines of men, and transgressed the Law Matthew 15:9; with which He reproached them, and said, None of you does the Law. John 7:19 Well did He say, climbs up, not enters in, since to climb is the act of a thief intending to overleap a wall, and who does all with danger. Have you seen how He has sketched the robber? Now observe the character of the shepherd. What then is it?