Let us not then vex ourselves with others, injuring ourselves, and rendering our soul weak. For the vexation is not so much from our neighbors' wickedness, as from our weakness. Because of this, should any one insult us, we weep, and frown; should any one rob us, we suffer the same like those little children, which the more clever of their companions provoke for nothing, grieving them for small causes; but nevertheless these too, if they should see them vexed, continue to tease them, but if laughing, they on the contrary leave off. But we are more foolish even than these, lamenting for these things, about which we ought to laugh.
Wherefore I entreat, let us let go this childish mind, and lay hold of Heaven. For indeed, Christ wills us to be men, perfect men. On this wise did Paul also command, “Brethren, be not children in understanding,” he says, “howbeit in malice be ye children.”
Let us therefore be children in malice, and flee wickedness, and lay hold on virtue, that we may attain also to the good things eternal, by the grace and love towards man of our Lord Jesus Christ, to whom be glory and might, world without end. Amen.
Source: Homilies on the Gospel of St. Matthew (New Advent)