Mark 3:22-23

And the teachers of the law who came down from Jerusalem said, “He is possessed by Beelzebul! By the prince of demons he is driving out demons.”

Beelzebub

So Jesus called them over to him and began to speak to them in parables: “How can Satan drive out Satan?"

Modern readings tend to run lucifer and beelzebub and satan and so on all together, I think there's a lot of theology in what different entities were actually envisaged by the author, but I doubt I could do it justice.

FWIW, Beelzebub was the name of another semitic philistine god worshipped, and hence propaganda-ly referred to as a nasty demon in the bible. It literally means "lord of the flies". "Baal" meaning "lord" crops up elsewhere. And "zvuv" onomatopoeicly meaning fly, but with the vets turning into bets at some point during the transliteration process

Satan drive out Satan

I suspect this is partly placed here as a preemptive rebuttal to people who might accuse Jesus of black magic. "Some people will claim jesus was doing black magic. But this already came and Jesus' official response was..."

But what does it mean for something to be black magic?

There was a long essay about necromancy in DnD. This is similar, but I'm not sure if it's the one I actually read: http://dungeons.wikia.com/wiki/Tome_of_Necromancy_(3.5e_Sourcebook)/Morality

The gist was, was necromancy inherently evil? Or just prone to tempt people into evil uses, but itself morally neutral? And DnD never really specifies, being ambiguous or contradictory, and leaving different players and DMs to form their own assumptions.

If Beelzebub is a demon as commonly imagined, ie. quite evil, then consorting with him, even for potentially good ends, is indeed extremely suspect and probably a bad thing.

If black magic just says "he made people less ill and we don't understand how", then I'm suspicious that it's automatically "evil". To me, it seems like anything else: if you can't give any good reason WHY you should think it's evil, I don't see why it should be.

If you already have sufficient demonstration of the good intentions of God, and God says "if it looks like magic, it's bad", then you have good reason to trust him/her. But if you don't, then the God healing people seems like a good candidate for "the" God, even if it wasn't the God you started with (assuming there aren't other warning flags that there may be something wrong with them).

Jesus' argument that one demon wouldn't help cast out others could be read suggesting a specific theology, that all bad things come from a single source. Alternatively, it could be read as a metaphor for what I said above: rather than "it's not a demon, it must be from God" read as "it's not doing any harm, so it must be from a good source".

Mark 3:28-29

Truly I tell you, people can be forgiven all their sins and every slander they utter, but whoever blasphemes against the Holy Spirit will never be forgiven; they are guilty of an eternal sin.

Ooh, controversial.

It's understandable that Jesus is angry here. The teachers of the law are supposed to be a moral and theological authority, and having just seen the holy spirit heal someone, are accusing it of being a demon. If Jesus is right, it's clear why that's some nasty blasphemy.

On the one hand, I think it's understandable if Jesus spoke with vehemence over precision here (and in other places). Words are always imperfect: being imprecise (especially as a moral authority) is bad, but it's not always the MOST bad thing. For the usual analogy consider a parent and a child. If the child tried to have the parent cast out for being a demon, I think it would be entirely reasonable for the parent to say that was unforgivable, even if it was still possible, though unlikely, to reconcile later.

On the other hand, even if we take a fluffy Jesus-was-a-nice-guy-even-if-he-wasn't-God viewpoint, it's easy to get sucked into contorted explanations of why he was ALWAYS right, and gloss over things he said that might be bad as a moral example nowadays (whether or not there was a good reason for saying them).

From a theological standpoint, if you take forgiveness-by-God literally, is there a standard interpretation of this passage?

If you take Jesus-died-for-our-sins literally, does that only apply to people who died after Jesus? Were there things which were previously unforgivable sins which became forgiveable with Jesus' sacrifice -- either specific really bad ones like blaspheming against the holy spirit, or as some people would say, ALL sins? Or was forgiveness via God's grace available before Jesus' death, just very rare?