In first century Palestine, it was common to find sheep grazing on the hillsides, with a shepherd keeping watch over them. At evening, the shepherds would drive their sheep into make-shift pens, with only one entrance. The entrance to the sheepfold had no door or gate; at night the shepherd himself would guard the entrance by lying down across the threshold of the opening. Any sheep that thought to exit would literally have to walk over the shepherd. The shepherd here, truly made himself the gate, or the door, by which the sheep could come in and out safely.
Jesus uses this image for himself. He makes himself the passage by which all must go through if they are to inherit the kingdom of heaven. Those who pass through this Door, Jesus says, “…will be saved, and will go in and out, and he will find pasture.”
We must listen attentively for the voice of the Shepherd, He who has called us into the sheepfold, to know His voice and follow Him. How can we know Jesus’ voice if we cannot hear it with our ears?