Selection from Arcana Coelestia ~ Emanuel Swedenborg
As death is from no other source than sin, and sin is all that which is contrary to Divine order, therefore evil closes the very smallest and most invisible vessels, of which are composed the next larger ones, also invisible; for the vessels which are smallest of all and wholly invisible are continued from man's interiors. Hence comes the first and inmost obstruction, and hence the first and inmost vitiation* into the blood. When this vitiation* increases, it causes disease, and finally death. If, however, man had lived a life of good, his interiors would be open into heaven, and through heaven to the Lord; and so too would the very least and most invisible little vessels (the traces of the first threads may be called little vessels, on account of the correspondence). In consequence man would be without disease, and would merely decline to extreme old age, even until he became again a little child, but a wise one; and when the body could no longer minister to his internal man or spirit, he would pass without disease out of his earthly body into a body such as the angels have, thus out of the world directly into heaven.(Arcana Coelestia 5726)
*vitiation - a reduction in the value, or an impairment in the quality of something; to make faulty or defective.