"Drunkenness leads to stumbling. Pride leads to unholy thoughts. The drunkard will be punished not for his stumbling but for his drunkenness.
Those unclean and unspeakable thoughts come at us when we are praying, but, if we continue to pray to the end, they will retreat, for they do not struggle against those who resist them.
This unholy demon not only blasphemes God and everything that is divine. It stirs up the dirtiest and most obscene thoughts within us, thereby trying to force us to give up praying or to fall into despair. It stops the prayer of many and turns many away from the holy Mysteries. It has evilly and tyrannously wearied the bodies of some with grief. It has exhausted others with fasting and has given them no rest. It has struck at people living in the world, and also at those leading the monastic life, whispering that there is no salvation in store for them, murmuring that they are more to be pitied than any unbeliever or pagan.
Anyone disturbed by the spirit of blasphemy and wishing to be rid of it should bear in mind that thoughts of this type do not originate in his own soul but are caused by that unclean devil who once said to the Lord, “I will give you all this if only You fall down and adore me” (Matt. 4:9). So let us make light of him and pay no regard whatever to his promptings. Let us say, ‘Get behind me, Satan! I will worship the Lord my God and I will serve only Him’ (Matt. 4:10). May your word and your effort rebound on you, and your blasphemies come down on your own head now and in the world to come." To fight against the demon of blasphemy in any way other than this is to be like a man trying to hold lightning in his hands. For how can you take a grip on, seize, or grapple with someone who flits into the heart quicker than the wind, talks more rapidly than a flash, and then immediately vanishes? Every other kind of foe stops, struggles a while, lingers and gives one time to struggle with him. But not this one. He hardly appears and is gone again immediately. He barely speaks and then vanishes.
This particular demon likes to take up residence in the minds of simpler and more innocent souls, and these are more upset and disturbed by it than others. To such people we could quite rightly say that what is happening to them is due not to their own undue self-esteem but to the jealousy of the demons.
Let us refrain from passing judgment or condemnation on our neighbor. If we do, then we will not be terrorized by blasphemous thoughts, since the one produces the other.
The situation here is like that of someone shut up in his own house who overhears but does not join in the conversation of passersby. The soul that keeps to itself overhears and is disturbed by the blasphemies of devils who are merely transients.
Hold this foe in contempt and you will be liberated from its torments. Try cleverly to fight it and you will end up by surrendering, for the man who tries to conquer spirits by talk is like someone hoping to lock up the winds."
Saint John Climacus