Reprinted from Orthodox Prayer Life: The Interior Way with permission of St. Vladimir's Seminary Press.

At times our soul is suffocated and is, as it were, amid the waves; and whether a man reads in the Scriptures, or performs his liturgy, or approaches anything whatever, he receives darkness upon darkness. He leaves off [prayer] and cannot even draw nigh to it. He is wholly unable to believe that a change will occur and that he will be at peace. This hour is full of despair and fear; hope in God and the consolation of faith are utterly extinguished from his soul, and she is wholly and entirely filled with doubt and fear. Those who have been tried by the mighty waves of this dark hour know from experience the change that follows upon its completion. God does not leave the soul in these things an entire day, for otherwise she would perish, being estranged from the Christian hope; but he speedily provides her with an "escape" (1 Cor 10.13). But even if the oppression of this darkness should be prolonged, you should expect that a change to the better will proceed swiftly out of the midst of it. I admonish and counsel you, O man, if you do not have the strength to master yourself and to fall upon your face in prayer, then wrap your head in your cloak and sleep until this hour of darkness pass from you, but do not leave your dwelling. This trial befalls those especially who desire to pass their life in the noetic discipline, and who throughout their journey seek the consolation of faith. For this reason their greatest pain and travail is the dark hour when their mind wavers with doubt. And blasphemy follows hard upon this. Sometimes a man is seized by doubts in the resurrection, and by other things whereof we have no need to speak. Many times we have experienced all these things, and we have written of this struggle for the comfort of many. Blessed is he who patiently endures these things within the doors [of his cell]! Afterward, as the Fathers say, he will attain to a magnificent and enduring dwelling. This struggle, however, does not cease immediately, nor in an hour; nor does grace come once and for all and dwell in the soul, but little by little of one and the other: sometimes trial, sometimes consolation. A man continues in these things until his departure. In this life we should not expect to receive perfect freedom from this struggle, nor to receive perfect consolation. For thus is God pleased to govern our life here: that those who journey in the way should be in the midst of these things. To him be glory unto the ages of ages. Amen. (St Isaac the Syrian, Homilies 50, in The Ascetical Hom-ilies of Saint Isaac the Syrian, pp 241-42)