Saint John Climacus. "The Ladder of Divine Ascent". Step 26.
Demons and passions quit the soul entirely or for some length of time. No one can deny that. However, the reasons for such a departure are known to very few.
Some of the faithful and even of the unfaithful have found themselves in the position of being bereft of all passions except one, and that one proved so overwhelming an evil that it took the place of all the others and was so devastating that it could lead to damnation.
The material of the passions is done away with when consumed by divine fire. It is uprooted, and all evil urges retire from the soul unless the man attracts them back again by his worldly habits and by his laziness.
Demons leave us alone so as to make us careless, then pounce on our miserable souls. And those beasts have another trick, of which I am aware; namely, to depart when the soul has become thoroughly imbued with the habits of evil, when it has turned into its оwn betrayer and enemy. It is rather like what happens to infants weaned from the mother's breast, who suck their fingers because the habit has taken hold of them.
There is a fifth kind of dispassion. It comes from great simplicity and from admirable innocence. "To such is help rightly given by the God Who saves the upright of heart" (Ps. 7:11) and Who rids them of ill evil without their perceiving it. They are like infants who when undressed have no realization of the fact that they are naked.