Quote by St. Barsanuphius the Great ~ do everything with discernment

It is needful to do everything with discernment, and to take your own measure, so that you will not be confused later. To perform alms, fasting, or anything else at the highest degree (beyond one's limits or personal measure) lacks discernment, since later it will lead the one who performs them into confusion, despondency, and grumbling. Even God requires that which is according to the strength of man.
(St. Barsanuphius the Great, Instructions, 627)



Source:
http://orthodox.cn/patristics/300sayings_en.htm