Yeah, I think it was a reach to call hermeneutics a science, but then again the same argument could be made against evolution... but that's another subject for another thread

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As for annihilation, I'm not aware of a passage in the New Testament that would teach annihilation...
Eternal security is definitely one that could be argued either way from any individual group of passages, but everyone believes that Jesus will never cast us off... the only problem is that many don't like the idea that they
might might be able to renounce it...
The gospel is most clearly preached in 1st Corinthians 15. These are the main things.
Yes, there are disagreements within the church on all these things, but most of them are trivial. Order of service and worship style divide more church bodies than actual doctrine! People are people...