Matthew 18:15

15IfἘὰνnowδὲsinsἁμαρτήσῃagainstεἰςyouσὲtheὁbrotherἀδελφόςof youσου,goὕπαγεreproveἔλεγξονhimαὐτὸνbetweenμεταξὺyouσοῦandκαὶhimαὐτοῦaloneμόνου.Ifἐάνyouσουhe will hearἀκούσῃ,you have gainedἐκέρδησαςtheτὸνbrotherἀδελφόνof youσου·

And if your brother may sin against you, go reprove him between you and him alone. If he may hear you, you have gained your brother.