They have a sense of humor, and apparently don't take themselves too seriously, at least not today. From the BBC article on reactions to today's date 06/06/06:
Among the actual Satanist community, attitudes to
the big day vary. Rev. John D Allee is the founder of the First Church
of Satan in Salem, America, which split from the original Church of
Satan 12 years ago.
"I plan to take Lillee, my High Priestess, to the
opening of The Omen movie," says the self-styled Dark Pope. "Then it's
out for dinner."
The Temple of Set takes a more solemn view. This is
another breakaway from the Church of Satan, claiming a history of
several thousand years, and "formally incorporated in 1975 CE".
Louise Renard is a priestess and assistant to the
executive director in London. "There is nothing significant about that
day or that number" she says. "Unless the new Omen movie turns out to
be better than expected."
Vlad the antichrist
Meanwhile, Vexen Crabtree, the Minister of the London
Church of Satan, plans to go to one of the alternative clubs that are
celebrating 06/06/06. "My official take on it is that 666 is really
only a Christian number," he explains. "But any excuse for a party is a
good one."