
Augustine of Hippo
Catena Aurea · Johannesevangelium 10
Then said Jesus unto them again, Verily, verily, I say unto you, I am the door of the sheep. All that ever came before me are thieves and robbers: but the sheep did not hear them. I am the door: by me if any man enter in, he shall be saved, and shall go in and out, and find pasture. The thief cometh not, but for to steal, and to kill, and to destroy: I am come that they might have life, and that they might have it more abundantly. All that ever came before Me are thieves and robbers.
(Tr. xlv. c. 15) What is this, shall go in and out? To enter into the Church by Christ the Door, is a very good thing, but to go out of the Church is not. Going in must refer to inward cogitation; going out to outward action; as in the Psalm, Man goeth forth to his work. (Ps. 103:23)