Doctrina XII, De timore et poenis inferni (Migne, Patrologia Graeca, 88, 1752)Through the body, the soul is distracted from its passions and is comforted, it eats, drinks, lays itself down to rest, keeps company, finds diversion in loved ones. But when it goes out of the body, the soul remains alone with its passions, and ultimately it is tormented by them forever, dwelling upon them, consumed with their agitation, rent asunder by them, so that it is no longer able to remember God. For remembrance of God comforts the soul, as it says in the psalm: I remembered God and was gladdened [Ps. 76:4]. But the passions do not allow the soul even this. Will you learn by a parable what it is I say? Let one of you go and shut himself up alone in a dark cell, and for three days let him not eat, drink, lay himself down to rest, meet anyone, sing psalms, pray, or remember God in any wise. Then shall he learn what the passions do to him. And this while he is yet here, but how much more so after the soul goes out of the body, and will have given itself up to the passions and will be alone with them.
