2 Will you, then, still contend that you were not rightly deceived, when you are about to superintend the things which belong to God, and are doing that which when Peter did the Lord said he should be able to surpass the rest of the apostles, for His words were, “Peter, do you love me more than these?” Yet He might have said to him, “If you love me practise fasting, sleeping on the ground, and prolonged vigils, defend the wronged, be as a father to orphans, and supply the place of a husband to their mother.”
But as a matter of fact, setting aside all these things, what does He say? “Tend my sheep.” For those things which I have already mentioned might easily be performed by many even of those who are under authority, women as well as men; but when one is required to preside over the Church, and to be entrusted with the care of so many souls, the whole female sex must retire before the magnitude of the task, and the majority of men also; and we must bring forward those who to a large extent surpass all others, and soar as much above them in excellence of spirit as Saul overtopped the whole Hebrew nation in bodily stature: or rather far more. For in this case let me not take the height of shoulders as the standard of inquiry; but let the distinction between the pastor and his charge be as great as that between rational man and irrational creatures, not to say even greater, inasmuch as the risk is concerned with things of far greater importance.
He indeed who has lost sheep, either through the ravages of wolves, or the attacks of robbers, or through murrain, or any other disaster befalling them, might perhaps obtain some indulgence from the owner of the flock; and even if the latter should demand satisfaction the penalty would be only a matter of money: but he who has human beings entrusted to him, the rational flock of Christ, incurs a penalty in the first place for the loss of the sheep, which goes beyond material things and touches his own life: and in the second place he has to carry on a far greater and more difficult contest.
For he has not to contend with wolves, nor to dread robbers, nor to consider how he may avert pestilence from the flock. With whom then has he to fight? With whom has he to wrestle? Listen to the words of St. Paul. “We wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places.” Do you see the terrible multitude of enemies, and their fierce squadrons, not steel clad, but endued with a nature which is of itself an equivalent for a complete suit of armor.
Would you see yet another host, stern and cruel, beleaguering this flock? This also you shall behold from the same post of observation. For he who has discoursed to us concerning the others, points out these enemies also to us, speaking in a certain place on this wise: “The works of the flesh are manifest, which are these, fornication, adultery, uncleanness, lasciviousness, idolatry, witchcraft, hatred, variance, emulation, wrath, strife, backbitings, whisperings, swellings, tumults,” and many more besides; for he did not make a complete list, but left us to understand the rest from these.
Moreover, in the case of the shepherd of irrational creatures, those who wish to destroy the flock, when they see the guardian take to flight, cease making war upon him, and are contented with the seizure of the cattle: but in this case, even should they capture the whole flock, they do not leave the shepherd unmolested, but attack him all the more, and wax bolder, ceasing not until they have either overthrown him, or have themselves been vanquished. Again, the afflictions of sheep are manifest, whether it be famine, or pestilence, or wounds, or whatsoever else it may be which distresses them, and this might help not a little towards the relief of those who are oppressed in these ways.
And there is yet another fact greater than this which facilitates release from this kind of infirmity. And what is that? The shepherds with great authority compel the sheep to receive the remedy when they do not willingly submit to it. For it is easy to bind them when cautery or cutting is required, and to keep them inside the fold for a long time, whenever it is expedient, and to bring them one kind of food instead of another, and to cut them off from their supplies of water, and all other things which the shepherds may decide to be conducive to their health they perform with great ease.
Source: On the Priesthood (New Advent)