Angels can fail because God allows them to make decisions and they are lesser beings than the perfect God. They can go astray, but the task is legitimate. God never tells they aren't allowed to instruct people - "just shut up and babysit them".

How much of what the biblical writers believed about the supernatural world do I believe? They weren't us. We are products of the Enlightenment; they were not. So let's stop denying that reality. Rather than sitting in judgment on them from our Enlightenment perches, we ought to have them sit in judgment on us when it comes to informing us about the supernatural world. After all, what they wrote was ultimately overseen by God.

The powers of darkness are still part of the spiritual world - they don't become something else when they rebel against God. Disembodied believers are, by definition, also part of the spiritual world. So are God and Christ.

We like to pretend the core ideas of the faith are more palatable or workable within our modern rationalistic approach to Scripture than the stuff we want to call "too weird" because of our own intellectual sensibilities. The truth is they are not. So we come up with interpretations to eliminate the weirdness of the biblical worldview that makes us uncomfortable. Problem solved!

If you don't have the worldview of the people who produced the Bible - under inspiration no less, - you can't understand what they were trying to communicate in many respects. Biblical people weren't modern people. That's self-evident no matter how much we try to deny it.

We impose our modern worldview on the Bible to make it conform to our intellectual happy place. But we deceive ourselves into thinking this works or is legitimate. We fail to realize that the supernatural things we want to avoid are no more supernatural (or "weird") than the things that define the Christian faith. What's so "normal" about the virgin birth, the Trinity, the deity of Christ, the bodily resurrection of Christ, the hypostatic union of the incarnation (Jesus was 100% God and 100% man)?

We think "reading the Bible in context" means thinking about the handful of verses before and after the verses we're looking at on the page. That isn't the case. While that's important, context is so much wider than a handful of verses.