But did he slander you to others? And what is this? God is the one that is to demand the account, not they that have heard this. For to himself has he added occasion of punishment, so that not only for his own sins he should give account, but also of what he said of you. And upon you has he brought evil report with men, but he himself has incurred evil report with God.
And if these things are not sufficient for you, consider that even your Lord was evil reported of both by Satan and by men, and that to those most loved by Him; and His Only-Begotten the same again. Wherefore He said, “If they have called the Master of the house Beelzebub, much more shall they call them of His household.”
And that wicked demon did not only slander Him, but was also believed, and slandered Him not in ordinary matters, but with the greatest reproaches and accusations. For he affirmed Him to be possessed, and to be a deceiver, and an adversary of God.
But have you also done good, and received evil? Nay, in respect of this most of all lament and grieve for him that has done the wrong, but for yourself rather rejoice, because you have become like God, “Who makes the sun to rise upon evil and good.”
But if to follow God is beyond you, although to him that watches not even this is hard; yet nevertheless if this seem to you to be too great for you, come let us bring you to your fellow-servants, to Joseph, who suffered countless things, and did good unto his brethren; to Moses, who after their countless plots against him, prayed for them; to the blessed Paul, who cannot so much as number what he suffered from them, and is willing to be accursed for them; to Stephen, who is stoned, and entreating this sin may be forgiven them. And having considered all these things, cast away all anger, that God may forgive us also all our trespasses by the grace and love towards man of our Lord Jesus Christ, with whom to the Father and the Holy Ghost be glory, might, honor, now and always, and world without end. Amen.
Source: Homilies on the Gospel of St. Matthew (New Advent)