Maximus the Confessor: “carry out good to all men”
“I write these things not wishing to cause distress to the heretics or to rejoice in their ill-treatment — God forbid; but, rather, rejoicing and being gladdened at their return. For what is more pleasing to the Faithful than to see the scattered children of God gathered again as one? Neither do I exhort you to place harshness above the love of men. May I not be so mad!
I beseech you to do and to carry out good to all men with care and assiduity, becoming all things to all men, as the need of each is shown to you; I want and pray you to be wholly harsh and implacable with the heretics only in regard to cooperating with them or in any way whatever supporting their deranged belief. For I reckon it hatred towards man and a departure from Divine love to lend support to error, so that those previously seized by it might be even more greatly corrupted.”
St. Maximus the Confessor, Patrologia Graeca