​Actually, what kind of a disease is leprosy? What is its cause, and how can it be cured? Before we can clearly understand the spiritual correspondence, we must first answer these
questions. Leprosy is caused when - be it through debauchery, through unnatural eating and
drinking or through uncleanliness - a person has absorbed into his organism so many foreign and
poisonous substances that the entire human clock movement cannot go on working. In order to
restore the normal and natural action and administration in all parts of the body, human nature
projects all the foreign substances and poisons, which have been taken in for years, onto its largest and very important organ, the skin, which provides the most extended contact with the external world, thereby not only ridding itself of its foreign and troublesome burden but also, with the help of this poisonous irritant, stimulate the skin to support the whole organism with increased activity, thus helping to restore its former health.
Naturally, this disease can best be healed in the same way as it arose, that is, it came from the
inside to the outside, and the healing must be effected in this way, too. The spoilt blood, which has deposited its bad substances in the skin, must be replaced with new and healthy blood. Of course, externally the wounds must als be kept clean, so that all can be removed that is decayed and no longer of any use to the body and the way cleared for the poisons, which may still have to be eliminated.
Thus healing can take place when, by observing a natural way of living, the body can renew itself and ensure full strength for its organism and a long, healthy life for the respective person.
Here you have a short outline of the nature of leprosy as a physical disease. (The Lord’s Sermons, chap. 9)