Picture an enclosure in the middle of a filed surrounded by a wall of rocks. The walls are high enough to keep the sheep in and thieves out. An opening in the wall allows the sheep to enter and exit the fold. At night, the good shepherd lay across the opening . . . like a door to the sheepfold.
This is what Jesus had in mind when He said, “Truly, truly, I say to you, I am the door of the sheep. All who came before me are thieves and robbers, but the sheep did not listen to them. I am the door. If anyone enters by me, he will be saved and will go in and out and find pasture” (John 10:7-9).