From the Arcana Coelestia ~ Emanuel Swedenborg
As the conjunction of the Lord with the human race by means of the Word - or that of heaven with the world, it must be told how the case is with regard to this. They who do not know the nature of the Word, cannot possibly believe that by means of it there is a conjunction of the Lord with the human race, and of heaven with the world; and still less they who despise the Word, or make no account of it. But let them know that the heavens subsist by means of Divine truth, and that without it there would be no heavens, and that the human race subsists by means of heaven; for unless heaven flowed in with man, man would not be able to think at all, thus not to will anything rationally. In order therefore that heaven may subsist, and the human race by conjunction with it, the Word has been provided by the Lord, wherein is Divine truth for angels and for men, the Word in its spiritual and celestial sense being of such a nature as to contain within it angelic wisdom itself in so surpassing a degree that it is scarcely possible for a man to form any conception of its excellence, although in the letter it appears very simple and unpolished.From this it is evident that heaven is in its wisdom from the Word when it is being read by man, and then at the same time the man is in conjunction with heaven. To this end has such a Word been given to man. From this it follows that if this medium of conjunction were not in the world, conjunction with heaven would perish, and with this conjunction all good of the will and all truth of the understanding in man, and with these that very humanity which consociates man with man; consequently evil and falsity would be in full possession, whereby one society would perish after another. For it would be as when a man walks in thick darkness and stumbles wherever he goes; and it would be as when the head is in a delirium, in consequence of which the body is carried madly and insanely even to its destruction; and it would be as when the heart fails, causing the organs and members to cease to perform their uses, until the whole body dies.
Such would be the state of man unless heaven were conjoined with him, and heaven would not be conjoined with him unless there were the Word; or unless Divine truth were communicated immediately through angels, as in ancient times. When heaven is mentioned, the Divine also is meant, for the Divine of the Lord makes heaven; so that to be conjoined with heaven is to be conjoined with the Lord; and to be disjoined from heaven is to be disjoined from the Lord; and to be disjoined from the Lord is to perish; for the whole disposal of things for good, which is called Providence, is from this source; and were such disposal removed, all things would rush into evil, and so into devastation. From all this it can be seen what is the use of the Word; but few will believe that the Word is of such a nature and of so great a use.
(Arcana Coelestia 10452:2-4)