11 If any of you perchance wish to keep charity, brethren, above all things do not imagine it to be an abject and sluggish thing; nor that charity is to be preserved by a sort of gentleness, nay not gentleness, but tameness and listlessness. Not so is it preserved. Do not imagine that you then love your servant when you do not beat him, or that you then love your son when you give him not discipline, or that you then love your neighbor when you dost not rebuke him: this is not charity, but mere feebleness.
Let charity be fervent to correct, to amend: but if there be good manners, let them delight you; if bad, let them be amended, let them be corrected. Love not in the man his error, but the man: for the man God made, the error the man himself made. Love that which God made, love not that which the man himself made. When you love that, you take away this: when you esteem that, you amend this. But even if you be severe at any time, let it be because of love, for correction. For this cause was charity betokened by the Dove which descended upon the Lord. That likeness of a dove, the likeness in which came the Holy Ghost, by whom charity should be shed forth into us: wherefore was this?
The dove has no gall: yet with beak and wings she fights for her young; hers is a fierceness without bitterness. And so does also a father; when he chastises his son, for discipline he chastises him. As I said, the kidnapper, in order that he may sell, inveigles the child with bitter endearments; a father, that he may correct, does without gall chastise. Such be ye to all men. See here, brethren, a great lesson, a great rule: each one of you has children, or wishes to have; or if he has altogether determined to have no children after the flesh, at least spiritually he desires to have children:— what father does not correct his son?
What son does not his father discipline? And yet he seems to be fierce with him. It is the fierceness of love, the fierceness of charity: a sort of fierceness without gall after the manner of the dove, not of the raven. Whence it came into my mind, my brethren, to tell you, that those violaters of charity are they that have made the schism: as they hate charity itself, so they hate also the dove. But the dove convicts them: it comes forth from heaven, the heavens open, and it abides on the head of the Lord.
Wherefore this? That John may hear, “This is He that baptizes.” Away, you robbers; away, you invaders of the possession of Christ! On your own possessions, where you will needs be lords, you have dared to fix the titles of the great Owner. He recognizes His own titles; He vindicates to Himself His own possession. He does not cancel the titles, but enters in and takes possession. So in one that comes to the Catholic Church, his baptism is not cancelled, that the title of the commander be not cancelled: but what is done in the Catholic Church? The title is acknowledged; the Owner enters in under His own titles, where the robber was entering in under titles not his own.
Source: Homilies on the First Epistle of John (New Advent)