The doctrine that organises all of Swedenborg's theology is correspondence: everything in nature answers to something in the spiritual world, not by metaphor but by constitution, effects below corresponding to causes above. Scripture, on this account, is written entirely in correspondences, so that the literal narratives of Genesis or Exodus carry an unbroken internal sense about the regeneration of the soul, which his Arcana Coelestia undertakes to decode verse by verse. Heaven and hell, in the book of that name, are not assigned but chosen: after death every spirit gravitates to the society of those whose ruling love matches its own, and the Lord casts no one out. Angels and devils alike are former humans; marriage love continues in heaven; and all heaven together has the form of one grand human. He announced a Last Judgment as an event he had witnessed in the spiritual world in 1757, inaugurating a new Christian era without disturbing the visible sky.
Through all this Swedenborg remained a communicant Lutheran and organised nothing. The institutions came later: readers in England gathered after his death, and in 1787 a separate New Church held its first services in London, ordaining ministers and eventually carrying the teachings to America, where a general convention formed in 1817. The posthumous church remains small; the diffuse influence, on Blake, on Emerson, on spiritualism, and on the very idea that the other world is structured and describable, has been immense.