John Chrysostom

(Hom. lix. 2) Our Lord having reproached the Jews with blindness, they might have said, We are not blind, but we avoid Thee as a deceiver. Our Lord therefore gives the marks which distinguish a robber and deceiver from a true shepherd. First come those of the deceiver and robber: Verily, verily, I say unto you, He that entereth not by the door into the sheepfold, but climbeth up some other way, the same is a thief and a robber. There is an allusion here to Antichrist, and to certain false Christs who had been, and were to be. The Scriptures He calls the door. They admit us to the knowledge of God, they protect the sheep, they shut out the wolves, they bar the entrance to heretics. He that useth not the Scriptures, but climbeth up some other way, i. e. some self-chosen1, some unlawful way, is a thief. Climbeth up, He says, not, enters, as if it were a thief getting over a wall, and running all risks. Some other way, may refer too to the commandments and traditions of men which the Scribes taught, to the neglect of the Law. When our Lord further on calls Himself the Door, we need not be surprised. According to the office which He bears, He is in one place the Shepherd, in another the Sheep. In that He introduces us to the Father, He is the Door; in that He takes care of us, He is the Shepherd.