black sun just means that they are satanists, who believe that "death" is at the very core of people.
opposite to Christ's teaching, which was that Life is at the very core. this anon's experience is that Christians are correct. (I'm sure Buddhists and others believe this as well).
Easy to discern who worships whom: satanists are miserable, selfish people who are lost. Christians (and others who are reborn) are typically selfless, loving, most of the time. Not tied to this world for salvation, as they recognize eternal Life.