When tested by some trial you should try to find out not why or through whom it came, but only how to endure it gratefully, without distress or rancor.
Therefore we must not grow weary. We must be steadfast, immovable, always abounding in the work of the Lord, knowing that in the Lord our labor is not in vain (I Corinthians 15:58). Having once begun, we must not cease to perform deeds worthy of our repentance. To rest is the same as to retreat.
If we want to do something but cannot, then before God, Who knows our hearts, it is as if we have done it. This is true whether the intended action is good or bad.
There is a sin which is always 'unto death' [1 Jn 5:16]; the sin which we have not repented. Even a saint's prayers will not be heard for the unrepented sin. The person who repents correctly does not imagine that his sins are cancelled through his own effort; but knows that through this effort he makes peace with God.
The abstinent withdraws from gluttony, the uncovetous from covetousness, the silent from wordiness, the pure from attachment to sensory pleasures, the chaste from fornication, he who is content with what he has from love of money, the meek from agitation (anger), the humble from vanity, the obedient from objection, he who is honest with himself from hypocrisy; equally, he who prays withdraws from despair, the willing pauper from acquisitiveness, he who professes his faith from denying it, the martyr from idolatry – so you see that each virtue, performed even unto death, is nothing but withdrawal from sin; and withdrawal from sin is a natural action, not an action which could be rewarded by the kingdom.
One should not ponder divine matters on a full stomach, say the ascetics. For the well-fed, even the most superficial secrets of the Trinity lie hidden.
Those who have sinned must not despair. Let that never be. For we are condemned not for the multitude of evils, but because we do not want to repent...
It is not always possible to fulfill the usual rules; one must take circumstances into account and try to fulfill what they make possible, as far as one can. The demons themselves are not unmindful of this law. So, being in constant enmity with us, they prevent us from doing what is possible and urge us to do what is impossible.
Whether you pray with brethren or alone, try to pray not simply as a routine, but with conscious awareness of your prayer. Conscious awareness of prayer is concentration accompanied by reverence, compunction and distress of soul as it confesses its sin with inward sorrow.
The holy Fathers' counsel is to begin with small things, for, says Ephraim the Syrian, how can you put out a great fire before you have learned to quench a small one? If you wish to set yourself free from a great suffering, crush the small desires, say the holy Fathers. Do not suppose that the one can be separated from the others: they all hang together like a long chain or a net.