Selection from Arcana Coelestia ~ Emanuel Swedenborg
He who is skilled in anatomy and also in physics may know by investigation that as regards their bodily and material forms, the organs both of sense and of motion, together with all the viscera, correspond to various things that exist in the nature of the world; and thus that the whole body is an organ composed of the most secret things in the nature of the world, and in accordance with their secret forces of acting and their wonderful modes of flowing. For this reason man was called by the ancients a little world or microcosm.He who knows this may also know that whatever exists in the world and its nature does not come forth from itself, but from what is prior to itself; and that this prior cannot come forth from itself, but from something prior to itself; and so on even to the First, from whom the things that follow come forth in order. And as they come forth from this, they also subsist from it; for subsistence is a perpetual coming forth. Hence it follows that all things in nature both in general and in particular, down to its last things, have not only come forth from the First, but also subsist from the First; for unless they were perpetually coming forth, and unless there were a continuous nexus, from the First, and thus with the First, they would fall to pieces and perish in an instant.
Now as all and each of the things in the world and its nature come forth, and come forth perpetually, that is, subsist, from things prior to themselves, it follows that they come forth and subsist from a world above nature, which is called the spiritual world; and as in order that they may subsist or perpetually come forth there must be a continuous nexus with that world, it follows that the purer and more interior things which are in nature, and consequently which are in man, are from that world; and also that the purer and more interior things are such forms as can receive the influx. And as there is only one possible fountain of life, as in nature there is only one fountain of light and heat, it is evident that everything of life is from the Lord, who is the First of life. And because this is so, it follows that all and each of the things which are in the spiritual world correspond to Him, and consequently all and each of the things which are in man; for man is a little spiritual world in the least form. Hence also the spiritual man is an image of the Lord.
From all this it is evident that with man especially there is a correspondence of all things with the spiritual world, and that without this correspondence he cannot subsist even for a moment; for without correspondence there would be nothing continuous from the very being of life, that is, from the Lord; thus there would be what is unconnected; and what is unconnected is dissipated as a nothing. The reason why correspondence with man is more immediate and hence closer, is that he has been created to apply to himself the life from the Lord, and thence into the capacity of a possible elevation by the Lord above the natural world in regard to his thoughts and affections, and thereby to think of God and to be affected with the Divine, and thus to be conjoined with Him, quite differently from the lower animals. And when the bodily things of this world are put away, those die not who are thus capable of being conjoined with the Divine, because their interiors remain conjoined with Him.
(from Arcana Coelestia 4523-4525)