Augustine of Hippo

For short periods and at prescribed times, power has been given to the demons to incite people whom they control to exercise a tyrannical hostility to the City of God. Thus, they are able not only to receive sacrifice from those who offer it and to seek it from those who are well disposed but also to extort it violently from the unwilling by means of persecutions. However, this power is not a menace to the church but rather an advantage, since it helps to fill up the number of its martyrs. And these the City of God esteems as its most illustrious and honored citizens, just because they have resisted the impious so valiantly, even "to the shedding of blood, striving against sin."