'Door' in the Bible

Verily, verily, I say to you, He that enters not in by the door to the fold of the sheep, but mounts up elsewhere, he is a thief and a robber;

but he that enters in by the door is the shepherd of the sheep.

Jesus therefore said again to them, Verily, verily, I say to you, I am the door of the sheep.

I am the door: if any one enter in by me, he shall be saved, and shall go in and shall go out and shall find pasture.

but Peter stood at the door without. The other disciple therefore, who was known to the high priest, went out and spoke to the porteress and brought in Peter.