Sir 6:17

“The gift of a full and perfect friendship cannot last if it is not among people of similar virtue. And this is what the holy Fathers taught, establishing certain stages in order to arrive at a perfect and unchanging condition of friendship. They said that the first step of true friendship is to despise earthly things and all possessions. Second, everyone should put in check his own will in order to avoid thinking that he is the only wise and sensible person around, preferring his own opinions to those of his neighbor. Third, they said that he should know to defer everything, even the things that he considers useful and necessary, when it will benefit charity and peace. Fourth, he should be convinced that he must not anger himself for no reason at all, whether the anger is just or unjust. Fifth, he should desire that the anger of his brother be assuaged like his own, even if that anger rises against him without reason, knowing that the pain of the one is equally damaging to both; if he lashes out against someone else, he will make every effort to remove that offense of his brother as well. Finally, he should believe that every day might be his last, which sentiment undoubtedly brings about the death of any vice. This conviction not only leaves no place for any sadness in our heart but furthermore stops any movement of evil desire and impedes all sins. Whoever, then, respects these things cannot experience or carry out the bitterness of anger and discord.”