Let us not be troubled when it befalls us to be plunged into darkness, especially if we are not responsible for it. You must realize that this darkness enshrouding you has been given you by God's providence for reasons known to him alone. Sometimes indeed our soul is engulfed by the waves and drowned. Whether we give ourselves to the reading of scripture or to prayer, whatever we do we are increasingly imprisoned in darkness… it is an hour filled with despair and fear. The soul is utterly deprived of hope in God and the consolation of faith. It is entirely filled with perplexity and anguish.
But those who have been tested by the distress of such an hour know that in the end it is followed by a change. God never leaves the soul for a whole day in such a state, for then hope would be destroyed…rather he allows it to emerge very soon from the darkness.
Blessed is he who endures such temptations… For, as the Fathers say, great will be the stability and the strength to which he will come after that. However, it is not in one hour or at one stroke that such a combat is concluded. Nor is it at one moment, but gradually, that grace comes to take up its dwelling completely in the soul. After grace, the trial returns. There is a time for trial. And there is a time for consolation.
ISAAC OF NINEVEH Ascetic Treatises, 57