My story will take place on Earth as well as other planets. Its a sci-fi story that is going to deal with a war between Gods humans and the Devils own race of demon warriors. My antagonist will basically be the anti-christ and my MC will be his direct opposite by the end of the story. I will be taking many liberties on what most people think that God and the Devil can and cant do and was just concerned that some readers would be distracted by this since the story is still based on Earth in the future. Does anyone think something like this will be a problem and am I just better off creating my own worlds with its own religion?
A lot of books take liberties with religion. As long as it seems based in the reality of your book, you should be fine. I'd just try to never refer to the religion in the book as Christian in order to avoid offending anyone.
I too think your idea is totally fine. I would never suggest that you won't offend anyone. Religion is, after all, very personal to some people and there are those who are bound to take exception to unorthodox religious imagery. Those people are in the minority however, and I wouldn't let a thing like that stop you if you're really committed to this idea.
I suggest that you read "Good Omens: The Nice and Accurate Prophecies of Agnes Nutter, Witch", "American Gods", "The Da Vinci Code" and anything by Robert Rankin. They all have similar elements. OK, most of them would be considered comedies but they all subvert the religions they are talking about. I think the trick in this instance is to say that humans got it wrong. That way you're not debunking anyone's religion, as such, just saying that humans are fallible. Even so, I would steer clear of the allegory of something like "The Satanic Rites". That book is really quite dull, and I think that is because it relies too heavily on the shock of the subject matter to get what is a rather empty subject across.
Oh don't worry, there's always going to be some overly insecure theist (or for that matter, anyone) who will take offense from your writing, even if religion wasn't a focus point of the plot. As long as God and co.'s powers remain consistent and are used realistically (consider their motivations and such like any other character) then the vast majority of your readers will treat them no differently than if you used a high fantasy setting. It's only fiction, after all. If you like it, go for it.
i agree with Onemorenameless, just write it, religion is a personal belief, they either will accept or reject but dont' let that stop you from writing what you want to
as noted above, it's done all the time... write whatever you want and don't worry about what this or that person will think of it... the only thing that will matter ultimately, is if a publisher will think it can make money for you both...
It'll depend on who you ask. Some will be offended some won't. As a result you shouldn't care what other folk think . People are fickle anyhow. If they don't like it, they'll probably overlook the glaring flaws and find one little nit pick to complain about. The Da Vince Code is as inaccurate as humanly possible in portraying the early history of Christianity, but all christians ignored all that and focused on one aspect of the book. Write it however. It won't be the first time liberties have been taken won't be the last. If people don't like it, i suggest putting in big bold words right on the cover "If you don't like it don't read it!" You could probably avoid a lot of attention by not being to specific about the god and devil thing and portraying them as more abstract ideas than actual representations of the real characters that exist in religion, but again. You're the writer.
From the mention of planets, I was lead to beleive that this would be a story rather Roman or Greek in basis. If so, I'm sure that you understand what I am getting at. It's been done before, but perhaps not well. If you have the time and/or patience, it will almost certainly do you well to read medieval classics such as Dante's "The Devine Comedy." Well.... perhaps not that! - it's scary lol! The point that I am trying to make is that you may want to read medival or Victorian ideas of a savior god (of whatever religion) and his/her nemisis. It can become very cliche. That's why I think that an understnading of the more underlining or subtle ideas of religious archetypes is important. Sorry...that's the best that I can do...