Jean-Claude Larchet

“The demonic etiology ofcertain illnesses is affirmed by the Scriptures: explicitly in the prologue to the Book ofJob (Job 2:6-7), and implicitly in tbe words of the Apostle Peter, "God anointed Jesus of Nazareth with the Holy Spirit and with power; ... he went about doing good and healing all that were oppressed by the devll, for God was with him" (Acts 10:38). In addition, there are numerous biblical accounts of miracles where the demonic origin of illness clearly appears. The Fathers also affirm such an etiology. This recognition of a demonic etiology does not prevent the Fathers from admitting as well a biological, organic or functional etiology as parallel or secondary. Far from excluding physical causality, the "metaphysical" or spiritual origin of illness includes the physical aspect, recognizing it to be a necessary vehicle for manifesting the demonic.”
― Jean-Claude Larchet, The Theology of Illness

“God, who envisions the salvation of man and through man of the entire universe, does not allow the forces of evil to submerge and destroy His creation. and nature remain partially protected by His Providence, which imposes certain limits on the negative activity of the Devil and his demons. Thereby God stabilizes the cosmos in its slide toward nothingness, establishing a certain order in the very heart of disorder. Even if man has lost the "likeness" ofGod which he began to acquire, he nevertheless remains bearer of the divine "image," even if that image is veiled, obscured and deformed. Thus man is not totally deprived of grace. Even in his weakness he retains sufficient spiritual power to be able, if he wishes, to turn again toward God and to obey the commandments which he continues to receive from Him (Dt 30:11-19). And thereby he is able to maintain, according to God's own promise, a certain mastery over nature (cf. Gen 9:1-2).
Nonetheless, this new balance remains fragile. Man and nature have become a battleground where evil and good, death and life, wage a permanent, merciless combat against each other. This combat is made evident by sickness, infirmity and suffering; and until the Incarnation of Christ, its outcome was uncertain.”
― Jean-Claude Larchet, The Theology of Illness