Even as Sodom and Gomorrha, and the cities about them in like manner, giving themselves over to fornication, and going after strange flesh, are set forth for an example, suffering the vengeance of eternal fire.
Just like Sodom and Gomorrah and the other nearby cities, who let themselves do bad things like having sex with people they shouldn't and wanting others they didn't know, they are shown as a warning. They now suffer from a very bad fire that never goes away.