Having entered by the door, according to God’s will and testimony, He was, for every other person, Himself “the door,” that which God had ordained as the means of having part in His blessings.
It is not the sheep’s knowledge of the stranger that keeps it from the snares which he tries to set for it, but there is one voice which is known by the sheep, the voice of the Good Shepherd, and they know that what they hear is not that voice. It is thus the simple are kept; the wise wish to know everything and are deceived. The voice and the Person being known encourage and authorize the sheep to follow them.
In the hardness of its heart, Israel remains in the fold. It will not enter in through Christ, the door of the sheep, but if anyone enters by that door, he shall be saved. Salvation was found in the Shepherd, that which the fold could not give. The sheep should be free. The fold afforded a kind of security the security of a prison. But it would find pasture; it would be fed in the rich pastures of God.
It is Christianity in contrast with Judaism. Christianity was salvation, liberty and divine food. Security is no longer imprisonment, but the care of the Good Shepherd. Free under His care, the sheep feed in safety in the vast and rich pastures of God.