Yeah, I'm not actually advocating satanist assemblies since satan is just another god like jehovah or allah etc.
As for lessons from the bible. I can think of a few.
Solidgold has already pointed out the homophobia and misogyny.
#1 If mistreated by a government it's ok to steal from the ordinary citizens.
(read about Moses telling the children of israel to 'borrow' jewelry from those Egyptians who trusted them)
#2 If you want a place to live, but there are already people living there then it's ok to slaughter men, women and children to make room. (also Moses, but a little later on)
#3 If someone does you wrong it's ok to take it out on their children and grandchildren. (Several places in the bible, but I can find them if you are not familar with the book)
#4 If the law of a country doesn't fit with your religion than it's ok to break it.
#5 If you have trouble with your neighbours just offer them your virgin daughters to rape to buy them off. (see Lot)
#6 If someone (even children) disrespects you then it's ok to kill them horribly.
(See isaiah and the bears)
The bible is full of these and even if you stick to the 'nice' bits in assembly you are still teaching children that this book is a source of moral guidence. Teach them about it by all means just like you would the holocaust and the nazi's. Just don't require them to worship it.