Brethren, let no one blaspheme against God or grumble at the time of tribulation. He should instead cast his burden on him who cares for his life and say: “O God, my hope and my supporter, manage my life according to your own will. The gall you choose for me is sweeter than the honeycomb I choose for myself”…
As for the devil of blasphemy, he incites the soul to blame God, to blaspheme against him; he stirs doubts concerning the divine mysteries and the Holy Virgin Mary. Man is given to think that his soul is the source of all these blasphemies. His bones dry up from distress, and he grieves bitterly over his soul.
Be not troubled, my brother, do not blame yourself. For your soul is not the speaker. She only hears what the devil says, and even this is against her will. And the proof of this is that when these blasphemies stop, the soul rejoices; she becomes enlightened and is comforted in her faith.
This kind of blasphemy appears particularly during prayer, singing, and reading…One is bombarded by these thoughts, although his soul wants only to praise God. But these thoughts are not counted as blasphemy. For God distinguishes the praises of the loving soul from the blasphemies of the deceitful devil…In this trail, the soul almost undergoes the “great tribulation.” Bitter in heart, yearning for death, the wholly body turbid…The devil exerts his utmost pressure on the soul to make her give up and lose hope…but blessed is he who holds out in such tribulation. Great indeed will be his reward!
John of Dalyatha, Homilies on the Devils of Fornication & Blasphemy, in “Spiritual Elder”.