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.
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.
When you go to your spiritual father for confession, do not bring yourself as an accuser of other people, saying, 'he said this,' and 'so-and-so said that'. . . but speak about your own doings, so that you may obtain forgiveness.
Faith is an eye that enlightens every conscience, and imparts understanding; for the Prophet saith, And if ye believe not, ye shall not understand (Is. vii, 9).
Prayer is truly a heavenly armor, and it alone can keep safe those who have dedicated themselves to God. Prayer is the common medicine for purifying ourselves from the passions, for hindering sin and curing our faults. Prayer is an inexhaustible treasure, an unruffled harbor, the foundation of serenity, the root and mother of myriads of blessings.
Join to every breath a sober invocation of the name of Jesus and the thought of death with humility. Both these practices bring great profit to the soul.
The spiritual discipline of fasting is a tool for shifting the focus away from us and toward the Lord and our brothers and sisters in whom we encounter Him each day. If we distort fasting into a private religious accomplishment to prove how holy we are, we would do better not to fast at all. That would simply be a way of serving ourselves instead of God and those who bear His image and likeness. In Lent, our focus must be set squarely on Christ and His living icons, not on us. The fundamental calling of the Christian life is to become like our Lord, Who offered Himself up for the salvation of the world purely out of love. If we are truly in communion with Him, then we too must offer up ourselves for our neighbors. And as He taught in the parable of the Good Samaritan, there are no limits on what it means to be a neighbor to anyone who is in need, regardless of nationality, culture, or anything else. Those who limit their concern for people according to such standards place serving the kingdoms of this world before fidelity to the Kingdom of God.
Amongst the higher powers all things are done in due order, and with them there are limitations of honor or ministry, and boundaries are set for the glory of each by God who apportions all things as He sees fit. Yet there is a single yoke laid upon all, and they serve at the bidding of the Lord, not regarding their servitude as unworthy, but counting the reality of it as a source of honor and glory.
The view we take of our Savior's dispensation is the view of the holy fathers who preceded us. By reading their works we equip our own mind to follow them and to introduce no innovation into Orthodoxy.