The image of our Lord as the Good Shepherd is a very ancient one in Christian iconography, where He is depicted as a beardless youth carrying a lamb around his neck. However, whilst the good shepherd image also appears in classical pagan art, where the same figure represents benevolence and philanthropy, for early Christians – forced to elude discovery by their persecutors – it immediately resonated with our Lord’s proclamation of himself as the “good shepherd” in today’s Gospel as well as with John the Forerunner’s proclamation of the “Lamb of God, which taketh away the sin of the world” (John I: 29).
Today’s Gospel extract, however, begins with our Lord’s warning against false shepherds, which He does by making contrasts between the true or good shepherd and the imposter, whom He stigmatises as a stranger, a thief, a robber and a hireling. The true shepherd enters by the door of the sheepfold, which the gatekeeper opens for him, he knows his sheep by name and the sheep follow him because they know his voice. The false shepherd, by contrast, “climbs in by another way”, and the sheep, rather than follow, will flee from him.
How are we to interpret this figurative language. The Gospel tells us that when the Lord spoke in this way “they did not understand what he was saying to them.” The first thing we might want to note is that these sheep are well maintained, being gathered into a sheepfold rather than allowed to wander and go astray. The pen or fold might be constructed of dry stone walls, or fencing and sometimes simply of thorn bushes but always with a single door, which the shepherd himself guarded, so when our Lords says, “I am the door of the sheep” we know exactly what he means. The purpose is solely protective because sheep are highly vulnerable. They have small brains, poor eyesight and hearing and no defensive devices like teeth, claws or scales. They tend to run in panic when scared, follow the sheep in front of them without caring where it is going and if there is a ditch into which they might fall, a river in which they might drown or a thorn bush in which they might become entangled, they are pretty good at finding it.
The fathers of the Church are in agreement that the sheepfold is an image of the Christian church, though they differ slightly in their interpretation of the door. St. John Chrysostom refers to the door as the Scriptures
“For they bring us to God and open to us the knowledge of God. They make us his sheep. They guard us and do not let the wolves come in after us. For Scripture, like some sure door, bars the passage against heretics, placing us in a state of safety as to all that we desire and not allowing us to wander. And, if we do not undo Scripture, we shall not easily be conquered by our enemies.”
St. Augustine of Hippo argues that Christ Himself is the doorman, the door and the shepherd,
“For what is the door ? The way of entrance. Who is the doorkeeper ? He who opens it. Who then, is he that opens himself, but he who reveals himself to sight ? … If you seek another person for doorman, take the Holy Spirit … of whom our Lord below said, ‘He will guide you into all truth.’ What is the door ? Christ. What is Christ ? The truth. Who opens the door but the one who will guide you into all truth ?” 
When I first visited a traditional Egyptian desert monastery and was shown the sturdy Kasr, or fortress, which dominate these ancient habitations, I noted that the original entrance was not by a door in the wall but by a hole in the floor by which visitors were winched up one at a time. Being more familiar with mediaeval English castles I observed that it was also a good vantage point from which to repel invaders with stones, rocks and boiling oil, but was reminded by the rather shocked monk that the monastic fortress was only defensive. The same can be said for the sheepfold.
So, if we follow the analogy of the church and the sheepfold we must recognise that we are the sheep – not a very flattering image, but one which we recognise as apt – and we are highly vulnerable. (Isaiah LIII: 6) reminds us that, “All we like sheep have gone astray; we have turned – every one – to his own way.” So what is it from which we need protecting ? In verse one our Lord has already mentioned “thieves and robbers” – basically rustlers – and in verse 12 he mentions the wolves. Added to which is our natural propensity to wander off and get into life-threatening situations. Clement of Alexandria makes the analogy more specific,
“These are rapacious wolves hidden in sheepskins, human traffickers, and opportunistic soul seducers, secretly, but [later] proved to be robbers. They strive by fraud and force to catch us who are unsophisticated and have less power of speech.”
I particularly like that expression, “opportunistic soul seducers” because it emphasises the spiritual nature of our plight, of the need to protect us from the dangers to the soul.
The rustler is intent on stealing us away from the good shepherd solely for his own purpose and profit. We can expect nothing from one who is dishonest and puts his own gratification first. The wolf seeks to devour us. He will show us no mercy, his only intent is our destruction. Compare these to the good shepherd who will actually lay down his life for his sheep. It is hardly surprising that St.Philip, when instructing the Ethiopian eunuch (Acts VIII: 32) uses Isaiah’s prophecy (LIII: 7) about the Christ,
“He was led as a sheep to the slaughter; and like a lamb dumb before his shearer, so opened he not his mouth.”
The great hymnographer, St. Ephraim the Syrian proclaims,
“Blessed be the Shepherd Who became a lamb for our reconciliation.
From earliest times the Church has seen the bishop as the ikon of Christ and used this pastoral symbolism to describe his role. He is a shepherd of souls; one who has the spiritual oversight over a company or body of Christians, as bishop, priest or minister – hence his designation as pastor’, from the Latin word for shepherd and its related word, pascere, ‘to feed’ whilst those under his spiritual care are appropriately designated as his ‘flock’. In the Western tradition the pastoral staff of the bishop is modelled on the shepherd’s crook and in both the Catholic and Byzantine traditions the bishops wear a long white scarf over his vestments known as the pallium or omophorion, symbolising their carrying the sheep on their shoulders. In Rome two lambs are presented to the Pope on the Feast of Saint Agnes (Agnus is the Latin for ‘lamb’), from whose wool the pallia are subsequently made. In the Byzantine tradition it is usual to speak of belonging to the diocese of a bishop, by using the expression of “coming under his omophor”, or pastoral protection.
The great fourth-century biblical scholar, Origen, noting the proclamation of the Lord’s nativity to shepherds, writes,
“Listen, shepherds of the churches ! Listen, God’s shepherds ! … For, unless that Shepherd comes, the shepherds of the churches will be unable to guard the flock well. Their custody is weak, unless Christ pastures and guards along with them. We read in the apostle: ‘We are co-workers with God.’ A good shepherd, who imitates the good Shepherd, is a co-worker with God and Christ. He is a good shepherd precisely because he has the best Shepherd with him, pasturing his sheep along with him.”
England’s Venerable Bede draws another parallel,
“The shepherds did not keep silent about the hidden mysteries that they had come to know by divine influence. They told whomever they could. Spiritual shepherds in the church are appointed especially for this, that they may proclaim the mysteries of the Word of God and that they may show to their listeners that the marvels which they had learned in the Scriptures are to be marvelled at.”
You will notice that the Lord contrasts himself with the “hireling”, a contemptuous expression for someone who makes reward or material remuneration the motive of his actions; a mercenary. He is the wolf in sheep’s clothing, whereas our Lord’s example, as St. Clement reminds us, is of a shepherd in sheep’s clothing.
However, it took the great Saint Cyril of Alexandria to expound this simple pastoral analogy and showing its cosmic significance with the greatest clarity and spiritual insight,
“Humanity, having yielded to an inclination for sin, wandered away from love toward God. On this account we were banished from the sacred and divine fold, I mean the realm of paradise. Having been weakened by this calamity, we became the prey of two bitter and merciless wolves: namely the devil who had beguiled humanity to sin; and death, which had been born of sin. But when Christ was announced as the good Shepherd over all, in the struggle with this pair of wild and terrible beasts, he laid down his life for us. He endured the cross for our sakes that by death he might destroy death.”
We often overlook the rigors and hardship which the good shepherd has to endure in order to tend his sheep, whilst our Lord’s parable of the Lost Sheep (Luke XV: 3-7 and Matthew XVIII: 10-14) demonstrates the infinite pains to which a good shepherd will go to save his sheep. Indeed, I recall once reading a sad report of youngsters who had drowned while trying to save their pet dog. We know the extent to which a caring heart will go to try to save an animal from destruction: how much more a loving Saviour.
 Homilies on the Gospel of John: 59.2-3.
 Tractates of the Gospel of John: 45.5 & 46.2-4.
 Nativity Hymn II.
 Homilies on the Gospel of Luke, 12.2.
 Homilies on the Gospels 1, 7.