“Most assuredly, I say to you, he who does not enter the sheepfold by the door, but climbs up some other way, the same is a thief and a robber. But he who enters by the door is the shepherd of the sheep. To him the doorkeeper opens, and the sheep hear his voice; and he calls his own sheep by name and leads them out. And when he brings out his own sheep, he goes before them; and the sheep follow him, for they know his voice. Yet they will by no means follow a stranger, but will flee from him, for they do not know the voice of strangers.” Jesus used this illustration, but they did not understand the things which He spoke to them.
Then Jesus said to them again, “Most assuredly, I say to you, I am the door of the sheep. All who ever came before Me are thieves and robbers, but the sheep did not hear them. I am the door. If anyone enters by Me, he will be saved, and will go in and out and find pasture. The thief does not come except to steal, and to kill, and to destroy. I have come that they may have life, and that they may have it more abundantly.
“I am the good shepherd. The good shepherd gives His life for the sheep. But a hireling, he who is not the shepherd, one who does not own the sheep, sees the wolf coming and leaves the sheep and flees; and the wolf catches the sheep and scatters them. The hireling flees because he is a hireling and does not care about the sheep. I am the good shepherd; and I know My sheep, and am known by My own. As the Father knows Me, even so I know the Father; and I lay down My life for the sheep. And other sheep I have which are not of this fold; them also I must bring, and they will hear My voice; and there will be one flock and one shepherd. (Jn 10:1-16)

Here He declares Himself to be Master even as the Father, if so be that He is the Shepherd, and the sheep are His. See how He speaks  in a more lofty tone in His parables, where the sense is concealed; and gives no open handle to the listeners? What then does this hireling? He “sees the wolf coming, and leaves the sheep, and the wolf comes, and scatters them.” This those false teachers did, but He the contrary. For when He was taken, He said, “Let these go their way, that the saying might be fulfilled” (c. 18:8, 9), that not one of them was lost. Here also we may suspect a spiritual wolf to be intended; for neither did Christ allow him to go and seize the sheep. But he is not a wolf only, but a lion also.“Because our adversary the devil,” It says, “walks about as a roaring lion.” (1 Peter 5:8) He is also a serpent, and a dragon; for, “Tread you on serpents and scorpions.” (Luke 10:19)

Therefore, I beseech you, let us remain pasturing beneath this Shepherd; and we shall remain, if we obey Him, if we hear His voice, if we follow not a stranger. And what is His voice? “Blessed are the poor in spirit, blessed are the pure in heart, blessed are the merciful.” (Matthew 5:3, 8, 7) If we do so, we shall remain beneath the Shepherd, and the wolf will not be able to come in; or if he come against us, he will do so to his own hurt.

For we have a Shepherd who so loves us, that He gave even His life for us. When therefore He is both powerful and loves us, what is there to hinder us from being saved? Nothing, unless we ourselves revolt from Him. And how can we revolt? Hear Him saying, “You cannot serve two masters, God and money.” (Matthew 6:24) If then we serve God, we shall not submit to the tyranny of money. And truly a bitterer thing than any tyranny is the desire of riches; for it brings no pleasure, but cares, and envyings, and plottings, and hatred, and false accusations, and ten thousand impediments to virtue, indolence, wantonness, greediness, drunkenness, which make even freemen slaves, no, worse than slaves bought with money, slaves not to men, but even to the most grievous of the passions, and maladies of the soul.

Such a one dares many things displeasing to God and men, dreading lest any should remove from him this dominion. O bitter slavery, and devlish tyranny! For this is the most grievous thing of all, that when entangled in such evils we are pleased and hug our chain, and dwelling in a prison house full of darkness, refuse to come forth to the light, but rivet evil upon ourselves, and rejoice in our malady. So that we cannot be freed, but are in a worse state than those that work the mines, enduring labours and affliction, but not enjoying the fruit. And what is in truth worse than all, if any one desire to free us from this bitter captivity, we do not suffer it, but are even vexed and displeased, being in this respect in no better case than madmen, or rather in a much more miserable state than any such, inasmuch as we are not even willing to be delivered from our madness.

What? was it for this, O man, that you were brought into the world? Was it for this that you were made a man, that you might work in these mines, and gather gold? Not for this did God create you in His Image, but that you might please Him, that you might obtain the things to come, that you might join the choir of Angels. Why now do you banish yourself from such a relationship, and thrust yourself into the extreme of dishonour and meanness?

He who came by the same birth pangs with thee, (the spiritual birth pangs I mean,) is perishing with hunger, and you art bursting with fullness: your brother goes about with naked body, but you provide garments even for your garments, heaping up all this clothing for the worms. How much better would it have been to put them on the bodies of the poor; so would they have remained undestroyed, would have freed you from all care, and have won for you the life to come. If you do not wish them to be moth-eaten, give them to the poor, these are they who know how to shake these garments well.

The Body of Christ is more precious and more secure than a chest, for not only does It keep the garments safe, not only does It preserve them unconsumed, but even renders them brighter. Oftentimes the chest taken with the garments causes you the utmost loss, but this place of safety not even death can harm. With It we need neither doors nor bolts, nor wakeful servants, nor any other such security, for our possessions are free from all treacherous attacks, and are laid up under guard, as we may suppose things laid up in heaven would be; for to all wickedness that place is inaccessible.

These thing we cease not continually to say to you, and you hearing are not persuaded. The reason is, that we are of a soul which is mean, gaping upon the earth, groveling on the ground. Or rather, God forbid that I should condemn you all of wickedness, as though all were incurably diseased. For even if those who are drunk with riches stop their ears against my words, yet they who live in poverty will be able to look clearly to what I say. “But what,” says some one, “has, this to do with the poor? for they have no gold, or any such garments.” No, but they have bread and cold water, but they have two pennies, and feet to visit the sick, but they have a tongue and speech to comfort the bedridden, but they have house and shelter to make the stranger their inmate. We demand not from the poor such and such a number of talents of gold, these we ask from the rich. But if a man be poor, and come to the doors of others, our Lord is not ashamed to receive even a penny, but will say that He has received more from the giver, than from those who cast in much.

How many of those who now stand here would desire to have been born at that time, when Christ went about the earth in the flesh, to have talked and sat at meat with Him? Lo, this may be done now, we may invite Him more than then to a meal, and feast with Him, and that to greater profit. For of those who then feasted with Him many even perished, as Judas and others like him; but every one of those who invite Him to their houses now, and share with Him table and roof, shall enjoy a great blessing. “Come,” it says, “you blessed of My Father, inherit the Kingdom prepared for you from the foundation of the
world. For I was hungry, and you gave Me food: I was thirsty, and you gave Me drink: I was a stranger, and you took Me in; sick, and you visited Me; I was in prison, and you came unto Me.” (Matthew 25:34-36)

That then we may hear these words, let us clothe the naked, let us bring in the stranger, feed the hungry, give the thirsty drink, let us visit the sick, and look upon him that is in prison, that we may have boldness and obtain remission of our sins, and share those good things which transcend both speech and thought. Which may we all obtain, through the grace and loving-kindness of our Lord Jesus Christ, to whom be the glory and the might forever. Amen.

[St. John Chrysostom, Homily 59 on the Gospel of St. John]