Arcana Colestia 7298 [2] Be it further known that it is according to the laws of order that no one ought to be persuaded about truth in a moment, that is to say, that truth should be so confirmed in a moment as to leave no doubt whatever about it; because the truth which is so impressed becomes persuasive truth, and is devoid of any extension, and also of any yielding quality. Such truth is represented in the other life as hard, and as such that it does not admit good into it so as to become applicable. Hence it is that as soon as in the other life any truth is presented before good spirits by a manifest experience, there is soon afterward presented something opposite which causes doubt. In this way it is given them to think about it, and to consider whether it be so, and to collect reasons, and thus to bring that truth into their minds rationally. By this there is effected an extension in the spiritual sight in respect to that truth, even to its opposites; and thence it sees and perceives in the understanding all the quality of the truth, and thence can admit influx from heaven according to the states of the objects, for truths receive various forms according to the circumstances. This is the reason why the magicians were allowed to do as Aaron did; for thereby doubt was excited among the sons of Israel about the miracle, whether it was Divine; and thus an opportunity was given them of thinking and considering whether it was Divine, and of finally confirming themselves that it was so. 
 
Divine Providence 24. The conjunction of good and truth is provided by the Lord by means of relation; since the quality of a good is known only by its relation to what is less good, and by its contrariety to evil. From this comes all power to perceive and to feel, since from this comes the quality of these powers; for thereby every thing enjoyable is perceived and felt from the less enjoyable and by means of what is not enjoyable, every thing beautiful from the less beautiful and by means of the unbeautiful; and likewise every good, which is of love, from the less good and by means of evil; and every truth, which is of wisdom, from the less true and by means of falsity. In every matter, from the greatest to the least of it, there must be variety; and when there is variety also in its opposite from its least to its greatest, and there is equilibrium between them, then there is relation according to degrees on both sides; and the perception and sensation of the thing either increase or diminish. But an opposite, as we should know, may take away perceptions and sensations or may exalt them; when it mingles itself it takes away; but when it does not mingle itself it exalts; and for this reason the Lord exactly separates good and evil in man, that they may not be mingled, just as He separates heaven and hell.
 
 
Heaven and Hell 541. Hell is divided into societies in the same manner as heaven, and also into as many societies as heaven; for every society in heaven has a society opposite to it in hell, and this for the sake of equilibrium. But the societies in hell are distinct according to evils and their falsities, because the societies in heaven are distinct according to goods and their truths. That every good has an opposite evil, and every truth an opposite falsity, may be known from this, that there is not anything that has not reference to its opposite, and that its quality and degree is known from its opposite, and its degree; and this is the origin of all perception and sensation is derived. On this account the Lord continually provides that every society of heaven has its opposite in a society of hell, and that there  is equilibrium between the two.
 
 
True Christian Religion 763. It is according to order that a first should go forth to its last both in general and in particular, in order that variety may exist in all things, and through varieties every quality; for quality is perfected by means of differences relating to what is more or less opposite. Who cannot see that truth takes on its quality through the existence of falsity, and good likewise through the existence of evil, as light takes on its quality through the existence of darkness, and heat through the existence of cold? What would color be if there were no black and nothing but white? If it were otherwise the quality of intermediate colors could not but be imperfect. What is sensation apart from relation; and what is relation except to things opposite? Is not the sight of the eye obscured by looking at white only, and quickened by a color that inwardly derives something from black, such, for example, as green? Is not the sense of bearing dulled by the continued strain of one tone upon its organs, and stimulated by a modulation that is varied by relative sounds? What is the beautiful without relation to the unbeautiful? So in some pictures in order to present vividly the beauty of a virgin, an ugly face is placed beside the handsome one. What are joy and happiness without relation to what is joyless and unhappy? Will not one become insane by dwelling upon one idea only, uninterrupted by a variety that tends to things opposite? It is the same with the spiritual things of the church, the opposites of which have relation to evil and falsity, which, nevertheless, are not from the Lord, but from man who has freedom of choice which he can turn either to a good use or an evil use; comparatively as it is with darkness and cold, which are not from the sun but are from the earth, which by its revolutions in turn withdraws from the sun and returns to it; and without its turning from and to the sun there would be neither day nor year, consequently no person and no thing on the earth. I have heard that churches which are in different goods and truths, provided their goods relate to love to the Lord, and their truths to faith in Him, are like so many gems in a king’s crown.