[1 of 2] Swedenborg (1688-1772, Sweden): primary subject "Peace" (search under Inner Life/Love, Positive Emotion, Virtue, Will)": source "Heaven and Hell": detail "Section 288[3]"
That innocence and peace go together like good and its delight can be seen in little children, who are in peace because they are in innocence, and because they are in peace are in their whole nature full of play. Yet the peace of little children is external peace; while internal peace, like internal innocence, is possible only in wisdom, and for this reason only in the conjunction of good and truth, since wisdom is from that conjunction. Heavenly or angelic peace is also possible in men who are in wisdom from the conjunction of good and truth, and who in consequence have a sense of content in God; nevertheless, while they live in the world this peace lies hidden in their interiors, but it is revealed when they leave the body and enter heaven, for their interiors are then opened.

[2 of 2] Swedenborg (1688-1772, Sweden): primary subject "Peace" (search under Inner Life/Love, Positive Emotion, Virtue, Will)": source "Arcana Coelestia, vol.10": detail "Section 8455"
Peace is like dawn on the earth, which gladdens minds with universal delight; and the truth of peace is like the light of dawn. This truth, which is called the truth of peace, is the Divine Truth itself in heaven from the Lord, and affects universally all who are there, and makes heaven to be heaven; for peace has in it confidence in the Lord, that He rules all things and provides all things, and that He leads to a good end. When a man is in the faith of these things, he is in peace, for he then fears nothing, and no solicitude about things to come disquiets him. A man comes into this state in proportion as he comes into love to the Lord.
 All evil, especially self-confidence, takes away the state of peace. It is believed that an evil man is in peace when he is in gladness and tranquility because all things succeed with him. But this is not peace; it is the delight and tranquility of cupidities, which counterfeit a state of peace. But in the other life this delight, because opposite to the delight of peace, is turned into what is undelightful, for this lies hidden within it. In the other life the exteriors are successively unfolded even to the inmosts; peace is the inmost in all delight, even in what is undelightful with the man who is in good. So far therefore as he puts off what is external, so far the state of peace is revealed, and so far he is affected with satisfaction, blessedness and happiness, the origin of which is from the Lord Himself.
 Concerning the state of peace which exists in heaven it can be said that it is such that it cannot be described by any words, neither can it come into the thought and perception of man, so long as he is in the world, by means of any idea derived from the world. It is then above all sense. Tranquility of mind, content, and gladness arising from success, are relatively nothing; for these affect only his externals; whereas peace affects the inmost things of all — the first substances, and the beginnings of substances in man, and hence it derives and pours itself forth into the substantiates (‘formed from substantials’) and principiates (‘from principles’) and affects them with pleasantness, and affects the origins of ideas, consequently the ends of man's life, with satisfaction and felicity, and thus makes his mind a heaven.