5 If then God thus rejoices over the little one that is found, how do you despise them that are the objects of God's earnest care, when one ought to give up even one's very life for one of these little ones? But is he weak and mean? Therefore for this very cause most of all, one ought to do everything in order to preserve him. For even He Himself left the ninety and nine sheep, and went after this, and the safety of so many availed not to throw into the shade the loss of one. But Luke says, that He even brought it on his shoulders, and that “There was greater joy over one sinner that repents, than over ninety and nine just persons.” And from His forsaking those that were saved for it, and from His taking more pleasure in this one, He showed His earnestness about it to be great.
Let us not then be careless about such souls as these. For all these things are said for this object. For by threatening, that he who has not become a little child should not so much as at all set foot in the Heavens, and speaking of “the millstone,” He has brought down the haughtiness of the boastful; for nothing is so hostile to love as pride; and by saying, “It must needs be that offenses come,” He made them to be wakeful; and by adding, “Woe unto him by whom the offense comes,” He has caused each to endeavor that it be not by him. And while by commanding to cut off them that offend He made salvation easy; by enjoining not to despise them, and not merely enjoining, but with earnestness (for “take heed,” says He, “that you despise not one of these little ones”), and by saying, “Their angels behold the face of my Father,” and, “For this end am I come,” and “my Father wills this,” He has made those who should take care of them more diligent.
Do you see what a wall He has set around them, and what earnest care He takes of them that are contemptible and perishing, at once threatening incurable ills to them that make them fall, and promising great blessings to them that wait upon them, and take care of them, and bringing an example from Himself again and from the Father?
Him let us also imitate, refusing none of the tasks that seem lowly and troublesome for our brethren's sake; but though we have to do service, though he be small, though he be mean for whom this is done, though the work be laborious, though we must pass over mountains and precipices, let all things be held endurable for the salvation of our brother. For a soul is an object of such earnest care to God, that “He spared not His own Son.”
Wherefore I entreat, when morning has appeared, straightway as we come out of our house, let us have this one object in view, this earnest care above all, to rescue him that is in danger; I do not mean this danger only that is known by sense, for this is not danger at all, but the danger of the soul, that which is brought upon men by the devil.
For the merchant too, to increase his wealth, crosses the sea; and the artisan, to add to his substance, does all things. Let us also then not be satisfied with our own salvation only, since else we destroy even this. For in a war too, and in an engagement, the soldier who is looking to this only how he may save himself by flight, destroys the rest also with himself; much as on the other hand the noble-minded one, and he who stands in arms in defense of the others, with the others preserves himself also. Since then our state too is a war, and of all wars the bitterest, and an engagement and a battle, even as our King commanded us, so let us set ourselves in array in the engagement, prepared for slaughter, and blood, and murders, looking to salvation in behalf of all, and cheering them that stand, and raising up them that are down. For indeed many of our brethren lie fallen in this conflict, having wounds, wallowing in blood, and there is none to heal, not any one of the people, not a priest, no one else, no one to stand by, no friend, no brother, but we look every man to his own things.
By reason of this we maim our own interests also. For the greatest confidence and means of approval is the not looking to our own things.
Therefore I say, are we weak and easy to be overcome both by men, and by the devil, because we seek the opposite to this, and lock not our shields one with another, neither are fortified with godly love, but seek for ourselves other motives of friendship, some from relationship, some from long acquaintance, some from community of interest, some from neighborhood; and from every cause rather are we friends, than from godliness, when one's friendships ought to be formed upon this only. But now the contrary is done; with Jews and with Greeks we sometimes become friends, rather than with the children of the church.
Source: Homilies on the Gospel of St. Matthew (New Advent)