'Door' in the Bible

"Most certainly, I tell you, one who doesn't enter by the door into the sheep fold, but climbs up some other way, the same is a thief and a robber.

But one who enters in by the door is the shepherd of the sheep.

Jesus therefore said to them again, "Most certainly, I tell you, I am the sheep's door.

I am the door. If anyone enters in by me, he will be saved, and will go in and go out, and will find pasture.

but Peter was standing at the door outside. So the other disciple, who was known to the high priest, went out and spoke to her who kept the door, and brought in Peter.

Then the maid who kept the door said to Peter, "Are you also one of this man's disciples?" He said, "I am not."