Sleep is a particular state of nature, an image of death, inactivity of the senses. Sleep is one, but, like desire, its sources and occasions are many; that is to say, it comes from nature, from food, from demons, or perhaps, sometimes, from extreme and prolonged fasting, through which the flesh is weakened and at last longs for the consolation of sleep.
The Holy Fathers recommend 'moderate' fasting; one ought not to allow the body to be weakened too much, for then the soul, too, is harmed. Nor ought one to undertake fasting too suddenly; everything demands practice, and each one should look to his own nature and occupation. To choose among different kinds of food is to be condemned; all food is God-given, but it is advisable to avoid such kinds as add to the body's weight and appetite; strong spices, meat, spirituous drinks and such foods as are solely for the palate's enjoyment. For the rest, one may eat what is cheap and most easily available, they say. But by 'moderate' they mean one meal a day, and that one light enough not to fill the stomach to satiety.
The Lord often humbles the vainglorious by causing some dishonor to befall them. And indeed the first step in overcoming vainglory is to remain silent and to accept dishonor gladly. The middle stage is to check every act of vainglory while it is still in thought. The end—insofar as one may talk of an end to an abyss—is to be able to accept humiliation before others without actually feeling it.
You must set about rooting out the very desire to have things pleasant, to get on well, to be contented. You must learn to like sadness, poverty, pain, hardship. You must learn to follow privately the Lord's bidding: not to speak empty words, not to adorn yourself, always to obey authority, not to look at a woman with desire, not to be angry and much else. For all these biddings are given us not in order for us to act as if they did not exist, but for us to follow: otherwise the Lord of mercy would not have burdened us with them. If any man will come after me, let him deny himself, He said (Matthew 16:24), thereby leaving it to each person's own will ... and to each person's endeavor: let him deny himself.
No, the God of love and peace and complete sacrifice does not care to live in the midst of bustling and ado to please oneself, even if this is carried on perhaps under some kind of pretence. There is one way to make a test: if your peace of mind is troubled, if you become dejected or perhaps a little angry if for some reason you have to give up performing the good deed you had planned, then you know that the spring was muddy.
During the divine services, and at the very moment when the Mysteries (e.g., Holy Communion) are being accomplished, this vile enemy often blasphemes the Lord and the holy Sacrifice that is being consecrated. Wherefore, we clearly learn that it is not our soul that pronounces these unspeakable, godless and unthinkable words within us, but the God-hating fiend who fled from Heaven for uttering blasphemies against the Lord there too, as it would seem. For if these shameless and disgraceful words are my own, how could I worship after receiving the Gift? How can I praise and revile at one and the same time?
Stint your stomach and you will certainly lock your mouth, because the tongue is strengthened by an abundance of food. Struggle with all your might against the stomach and restrain it with all sobriety. If you labor a little, the Lord will also soon work with you.
No one in the face of blasphemous thoughts need think that the guilt lies within him, for the Lord is the Knower of hearts, and He is aware that such words and thoughts do not come from us but from our foes.