Darkness" is a state without light. "Light" is truth from the Lord, so "darkness" represents a state where truth is lacking. Here's a cogent passage from Arcana Coelestia: "The person who has yet to be regenerated is called 'a void and an empty earth', and also 'ground', in which no good or truth at all has been sown - 'void' where there is no good, and 'empty' where there is no truth. Consequently there is 'thick darkness', or stupidity and lack of knowledge about anything that has to do with faith in the Lord and so anything that has to do with spiritual and celestial life. (Arcana Coelestia 17)

2322. That 'Sodom' means the evil, especially those inside the Church, is clear from the meaning of 'Sodom' as evil that stems from self-love, dealt with in 2220, 2246. It means therefore people who are governed by such evil. People who understand the Word purely from the sense of the letter may imagine that 'Sodom' is used to mean a certain kind of foul behaviour that is totally unnatural, but in the internal sense 'Sodom' means evil that springs from self-love. Out of this evil all evils of every kind well up. And the evils that well up from it are in the Word called 'adulteries' and are described as such. This will be clear from those places in the Word which will be quoted at the end of this chapter.