Meditations 7.22.1
Marcus Aurelius to himself
Ἴδιον ἀνθρώπου φιλεῖν καὶ τοὺς πταίοντας. τοῦτο δὲ γίνεται, ἐὰν συμπροσπίπτῃ σοι, ὅτι καὶ συγγενεῖς καὶ δι’ ἄγνοιαν καὶ ἄκοντες ἁμαρτάνουσι καὶ ὡς μετ’ ὀλίγον ἀμφότεροι τεθνήξεσθε, καὶ πρὸ πάντων, ὅτι οὐκ ἔβλαψέ σε· οὐ γὰρ τὸ ἡγεμονικόν σου χεῖρον ἐποίησεν ἢ πρόσθεν ἦν.
It is a human distinction to love even those who go wrong. You can do this if it occurs to you at the same time that they are your kin, that they err through ignorance and unwillingly, that soon you will both be dead, and above all that the other person has not harmed you: they have not made your ruling faculty worse than it was before.