St. Maximus the Confessor (580-662 AD) tells us:

St. Maximus the Confessor (580-662 AD) tells us:  “A true friend is one who in times of trial calmly and imperturbably suffers with his neighbor the ensuing afflictions, privations and disasters as if they were his own.” (Philokalia II) The good saint continues: “’A faithful friend is beyond price’ (Ecclus 6:15), since he regards his friend’s misfortunes as his own and suffers with him, sharing his trials until death. Friends are many, but in times of prosperity. (cf. Pv. 19:4). In times of adversity you will have difficulty finding even one.” (Philokalia II) “’A faithful friend is a strong defense’ (Ecclus 6:14); for when things are going well with you, he is a good counselor and a sympathetic collaborator, while when things are going badly, he is the truest of helpers and a most compassionate supporter.” St. Maximus the Confessor,  (Philokalia II).