Against Celsus 8.44

But since the souls of those who die for Christianity out of piety, departing from the body with glory, destroyed the power of the demons and made their plotting against men weaker, for this reason, I think, the demons, having learned by experience that they are defeated and overcome by the martyrs of the truth, have been afraid to come back to taking vengeance; and so, until they forget the troubles they have suffered, it is likely that the world will be at peace with Christians. But when they gather their strength and, blinded by wickedness, wish again to take vengeance and persecute Christians, they will be overthrown again; and then again the souls of the pious, putting off their bodies for piety's sake, will overthrow the army of the evil one. And I think that the demons, perceiving that those who conquer and die for piety destroy their dominion, while those who are defeated by their sufferings and deny their worship of God become subject to them, sometimes contend hard with the Christians who are handed over, as though punished by their confession and relieved by their denial. One can see traces of this even in the judges, who are pained by those who endure the outrages and tortures, and exult when a Christian is defeated. For they do not do this out of what they think is kindness, since they see clearly that “the tongue” of those overcome by pain “has sworn, but the mind” is “unsworn.” Let this be said also in answer to “But these at least take severe vengeance on the blasphemer, who either flees and hides for this reason, or is caught and destroyed.” And if a Christian flees, he does not flee out of cowardice, but keeping his Teacher's command, and preserving himself pure for the salvation of others who will be helped.