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.
Rivalry over material possessions has made us forget the counsel of the Lord, who urged us to take no thought for earthly things, but to seek only the kingdom of heaven (cf. Matt. 6:33).
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.
Go, sell all that belongs to you and give it to the poor and taking up the cross, deny yourself; in this way you will be able to pray without distraction.
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.
A mind from which the thought of God has been carried away and which has thus become far removed from remembering Him, is also indifferent to sin with the outer senses. For such a mind can guide neither the hearing nor the tongue, since zest to work on itself has gone out of it.
Prayer demands that the mind should be pure of all thought and should admit nothing not belonging to prayer, even if it were good in itself. As if inspired by God the mind should withdraw from all things and hold its converse with Him alone.