Jesus Christ said that the Holy Spirit blows where it wills and you hear the sound of it, but cannot tell where it comes from and where it goes (Jn. 3:8). This means that a person cannot force the Holy Spirit to come to him or predict the time when He may decide to do so. You can only feel His touch when this happens. Indeed, the book of Acts states that when the Holy Apostles and other Christians received the gifts of the Holy Spirit, it was always unexpectedly. He seldom descends immediately on those beseeching Him but does so when it suits Him, as God, to do so. No one should attempt to foretell when or what gifts, if any, he will receive or to consider himself worthy of His descent! The Grace of the Holy Spirit is a gift of His endless mercy. And gifts by definition are given when it suits the giver, and only those deemed suitable by the giver.
When you shed floods of tears during prayer, do not exalt yourself for this, as though you were above many others. It is that your prayer has received help from above, so that, having zealously confessed your sins, you may incline the almighty to mercy by your tears.
In no art do the artists judge the result of their work by the tools they use, but they await the work's completion and by it judge the art. Adopting such a practice with regard to food, not placing all your hope on fasting, but fasting moderately and according to the amount of your strength, strive toward mental activity. In this way you can avoid pride and will not spurn God's good works, sending up praises to God for everything.
Prayer... by its action it is the reconciliation of man with God, the mother and daughter of tears, a bridge for crossing temptations, a wall of protection from afflictions, a crushing of conflicts, boundless activity, the spring of virtues, the source of spiritual gifts, invisible progress, food of the soul, the enlightening of the mind, an axe for despair, a demonstration of hope, the release from sorrow.
Put aside bodily considerations when you stand in prayer, lest the bite of a flea, a gnat or a fly deprive you of the greatest gain afforded by prayer.
Pray firstly to be purified of passions, secondly to be freed from ignorance and forgetfulness, and thirdly to be delivered from all temptation and forsaking.
Do not pray that things may be according to your desires, for they are not always in keeping with the will of God. Better pray as you were taught, saying: ‘Thy will be done’ on me (Matt. vi 10). And ask thus about all things, for He always desires what is good and profitable for your soul, whereas you do not always seek it.
It is important also to study our God-given faith in detail, since he who is indifferent toward truth is in danger of becoming easy prey for false teachers.
St. Paul says: 'The person engaged in spiritual warfare exercises self control in all things' (I Cor. 9:25). Aware of all that is said in divine Scripture, let us lead our life with self-control, especially in regard to food.
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.