Do not neglect the practice of the virtues; if you do, your spiritual knowledge will decrease, and when famine occurs you will go down into Egypt (Genesis 41:57, 46:6).
Peace of soul is acquired by perfect surrender to the Divine Will, without which nothing happens... He, in whose heart humility and meekness are reborn, will find true rest for his soul. He will be satisfied with everything, grateful for everything, peaceful and full of love for everybody. He will judge none and will feel no anger. His heart will be filled with divine sweetness, that is, he will feel in himself the Kingdom of God because God grants His grace only to the humble.
The late Athonite Father Tikhon used to say: The prayer, 'Lord Jesus have mercy on us' is worth one hundred drachmas, but 'Glory to God' is word one thousand. Glorifying God is more valuable than anything else, because in the first instance, people often say the Jesus Prayer when needing something; but when one glorifies God in the midst of suffering, it is an ascesis.