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.
If you have promised Christ to go by the strait and narrow way, restrain your stomach, because by pleasing it and enlarging it, you break your contract. Attend and you will hear Him who says: 'Spacious and broad is the way of the belly that leads to the perdition of fornication, and many there are who go in by it; because narrow is the gate and strait is the way of fasting that leads to the life of purity, and few there be that find it.'
Practice self-observation. And if you want to benefit yourself and your fellow men, look at your own faults and not those of others. The Lord tells us: 'Judge not, that ye be not judged,' condemn not that ye be not condemned. And the Apostle Paul says: 'Who art thou that judgest another man's servant?'
When we stand in prayer, those unclean and unspeakable thoughts (blasphemy) assail us; but if we continue praying to the end, they retire at once, for they do not fight those who stand up to them.
Even a pious person is not immune to spiritual sickness if he does not have a wise guide -- either a living person or a spiritual writer. This sickness is called prelest, or spiritual delusion, imagining oneself to be near to God and to the realm of the divine and supernatural. Even zealous ascetics in monasteries are sometimes subject to this delusion, but of course, laymen who are zealous in external struggles (podvigi) undergo it much more frequently. Surpassing their acquaintances in struggles of prayer and fasting, they imagine that they are seers of divine visions, or at least of dreams inspired by grace. In every event of their lives, they see special intentional directions from God or their guardian angel. And then they start imagining that they are God's elect, and often try to foretell the future. The Holy Fathers armed themselves against nothing so fiercely as against this sickness -- prelest.
Blessed is he who, though maligned and disparaged every day for the Lord's sake, constrains himself to be patient. He will join the chorus of the martyrs, and boldly converse with the angels.