Do not be in a hurry to make friends, but, if you make new friends, take care of the new friendship in every way by lifting all the burden of your neighbor, unless there is a risk of causing harm to your soul because the coldness and hostility between friends befog their judgement.
You should make friends those who kept their friendship with others pure in all circumstances and were not jealous of their friends when they were prosperous, nor were they indifferent when their friends were in misery.
Because, when their friends are unhappy, many would support and help them, but when they are prosperous, they can not bear to see their happiness, and those who do not show their true colors at the time of compassion are exposed by the passion of envy. So make friends, not the bad ones but the excellent ones.
Because most of the time the ethos of friends is judged by the people they love. Even if someone made a mistake, they could very easily correct it with the help of remarkable friends. However, bad friends are those who spoil whatever is already good in their character. The good friends make the shortcomings in matters of virtue make them feel less serious; on the contrary, the companion of the wicked make even the lightest virtue that one may have false.
Saint Photius the Great, Patriarch of Constantinople