Peace is Desired by All, but not For All
If there is no man who does not wish to be joyful, neither is there any one who does not wish to have peace. For even they who make war desire nothing but victory,—desire, that is to say, to attain to peace with glory. … For even they who intentionally interrupt the peace in which they are living have no hatred of peace, but only wish it changed into a peace that suits them better. They do not, therefore, wish to have no peace, but only one more to their mind. And in the case of sedition, when men have separated themselves from the community, they yet do not effect what they wish, unless they maintain some kind of peace with their fellow-conspirators. And therefore even robbers take care to maintain peace with their comrades, that they may with greater effect and greater safety invade the peace of other men.
And if an individual happen to be of such unrivalled strength, and to be so jealous of partnership, that he trusts himself with no comrades, but makes his own plots, and commits depredations and murders on his own account, yet he maintains some shadow of peace with such persons as he is unable to kill, and from whom he wishes to conceal his deeds. In his own home, too, he makes it his aim to be at peace with his wife and children, and any other members of his household; … For he sees that peace cannot be maintained unless all the members of the same domestic circle be subject to one head, such as he himself is in his own house. And therefore if a city or nation offered to submit itself to him, to serve him in the same style as he had made his household serve him, he would no longer lurk in a brigand’s hiding-places, but lift his head in open day as a king, though the same covetousness and wicked ness should remain in him.
–City of God XIX.12
Eternal Peace of the City of God
The peace of the body then consists in the duly proportioned arrangement of its parts. The peace of the irrational soul is the harmonious repose of the appetites, and that of the rational soul the harmony of knowledge and action. The peace of body and soul is the well-ordered and harmonious life and health of the living creature. Peace between man and God is the well-ordered obedience of faith to eternal law. Peace between man and man is well-ordered concord. Domestic peace is the well-ordered concord between those of the family who rule and those who obey. Civil peace is a similar concord among the citizens. The peace of the celestial city is the perfectly ordered and harmonious enjoyment of God, and of one another in God. The peace of all things is the tranquillity of order. Order is the distribution which allots things equal and unequal, each to its own place.
There is a nature in which evil does not or even cannot exist; but there cannot be a nature in which there is no good. Hence not even the nature of the devil himself is evil, in so far as it is nature, but it was made evil by being perverted. Thus he did not abide in the truth, but could not escape the judgment of the Truth; he did not abide in the tranquillity of order, but did not therefore escape the power of the Ordainer. The good imparted by God to his nature did not screen him from the justice of God by which order was preserved in his punishment; neither did God punish the good which He had created, but the evil which the devil had committed. God did not take back all He had imparted to his nature, but something He took and something He left, that there might remain enough to be sensible of the loss of what was taken. And this very sensibility to pain is evidence of the good which has been taken away and the good which has been left. For, were nothing good left, there could be no pain on account of the good which had been lost. For he who sins is still worse if he rejoices in his loss of righteousness.
–City of God XIX.13