I'm not a great example of living a sinless life, but let me try to explain two of those issues.
Hell: For humans it's referred to at the 2nd death. There is a "waiting room" type hell where nonbelievers go to await judgement day. That isn't eternal. After judgement day, those who don't make the cut simply cease to exist. They die in spirit. The fallen angels know what they are doing, and it was intended only for them. They suffer there for eternity.
Only one true God: It's easy to overthink this one, but I look at it as the stories all differ, so in the case of conflicting stories, only one or none can be true.
Might or might not help, but it's something to think about.
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