3 For whereas the greatest of evils, and those which make havoc of the whole world, had their entering in from pride:— for both the devil, not being such before, did thus become a devil; as indeed Paul plainly declared, saying, “Lest being lifted up with pride, he fall into the condemnation of the devil:” — and the first man, too, puffed up by the devil with these hopes, was made an example of, and became mortal (for expecting to become a god, he lost even what he had; and God also upbraiding him with this, and mocking his folly, said, “Behold, Adam has become as one of us”; and each one of those that came after did hereby wreck himself in impiety, fancying some equality with God:— since, I say, this was the stronghold of our evils, and the root and fountain of all wickedness, He, preparing a remedy suitable to the disease, laid this law first as a strong and safe foundation. For this being fixed as a base, the builder in security lays on it all the rest. But if this be taken away, though a man reach to the Heavens in his course of life, it is all easily undermined, and issues in a grievous end. Though fasting, prayer, almsgiving, temperance, any other good thing whatever, be gathered together in you; without humility all fall away and perish.
It was this very thing that took place in the instance of the Pharisee. For even after he had arrived at the very summit, he “went down” with the loss of all, because he had not the mother of virtues: for as pride is the fountain of all wickedness, so is humility the principle of all self-command. Wherefore also He begins with this, pulling up boasting by the very root out of the soul of His hearers.
“And what,” one may ask, “is this to His disciples, who were on every account humble? For in truth they had nothing to be proud of, being fishermen, poor, ignoble, and illiterate.” Even though these things concerned not His disciples, yet surely they concerned such as were then present, and such as were hereafter to receive the disciples, lest they should on this account despise them. But it were truer to say that they did also concern His disciples. For even if not then, yet by and by they were sure to require this help, after their signs and wonders, and their honor from the world, and their confidence towards God. For neither wealth, nor power, nor royalty itself, had so much power to exalt men, as the things which they possessed in all fullness. And besides, it was natural that even before the signs they might be lifted up, at that very time when they saw the multitude, and all that audience surrounding their Master; they might feel some human weakness. Wherefore He at once represses their pride.
And He does not introduce what He says by way of advice or of commandments, but by way of blessing, so making His word less burthensome, and opening to all the course of His discipline. For He said not, “This or that person,” but “they who do so, are all of them blessed.” So that though you be a slave, a beggar, in poverty, a stranger, unlearned, there is nothing to hinder you from being blessed, if you emulate this virtue.
Source: Homilies on the Gospel of St. Matthew (New Advent)