The Gnostic and Manichaean struggles had ripened the theologic idea that, although at times diseases are punishments by the Almighty, the main agency in them is Satanic.

The great fathers and renowned leaders of the early Church accepted and strengthened this idea.

Origen said: "It is demons which produce famine, unfruitfulness, corruptions of the air, pestilences; they hover concealed in clouds in the lower atmosphere, and are attracted by the blood and incense which the heathen offer to them as gods." St.Augustine said: "All diseases of Christians are to be ascribed to these demons; chiefly do they torment fresh-baptized Christians, yea, even the guiltless, newborn infants." Tertullian insisted that a malevolent angel is in constant attendance upon every person.

Gregory of Nazianzus declared that bodily pains are provoked by demons, and that medicines are useless, but that they are often cured by the laying on of consecrated hands.

St.Nilus and St.Gregory of Tours, echoing St.Ambrose, gave examples to show the sinfulness of resorting to medicine instead of trusting to the intercession of saints.