I'm in the odd position a lot of people are these days--I grew up going to church, where the Bible and its contents are expounded on at length--and then I went to college. Education tends to beat religion out of people. I'm not saying this to criticize education or religion or imply that those who can manage to juggle both are somehow better than those who can't. I say this because it's something I struggle with, something I know a lot of people struggle with--the church (and that's the church in general, not any specific flavor) almost always takes a literal interpretation of the Bible. And yet science and modern archaeological discoveries have proven repeatedly that a literal interpretation is not possible.
There's also the very real problem that throughout the course of history, the church (again, general, not specific) has elected to not include materials in the Bible because they didn't fit with the image the church was trying to project. You add in mistranslations and outright lies (James I of England and the whole witch thing) and at best you have a flawed document with major plot holes, at worst you have outright lies.
One of those books that didn't make it in to the Bible is the Book of Enoch. I've referenced it before and I probably will repeatedly, because it plays a huge part in the overall series arch of Winged. It tells the story of angels who looked down upon the people of earth, including the women, and wanted to be a part of it. They married women, fathered children on them, taught things like the art of war, divination, how to craft weapons and so on. Their children were larger than normal people--what some might call giants. In the eyes of God, these angels betrayed their purpose--they didn't watch over humanity, they didn't protect it: they corrupted it. This is the main reason why God turned them away, why he refused to allow them to reenter his presence for all eternity. According to Enoch, God flooded the Earth to erase these children of angels, these monsterous giants, so humanity once again had a chance.
We've all heard the story of Noah and the Ark. Most people have heard the story of David and Goliath--a giant among a race of giants. Both of these episodes are better understood with the information given in the Book of Enoch. So why isn't that information there?
Because it wouldn't fit with the safe, sterile image of angels the church wanted to present--continues to insist on presenting. Never mind the fact that one of the scriptures constantly touted is about God making man in his image--logic stands that God didn't just throw things together and hope for the best. There has to have been trial and error, room for improvement and growth. There also has to be some kind of blueprint to work from, something to goal for.
Why wouldn't it be creatures who have been around for millenia--like, I don't know, angels? Creatures who were also quite possibly created from the image of God.
And what about emotions, free will, personality? Again, even if you're going with blind faith, take a moment to think: where did God get the idea for anger, for pride--things that were already in place when Lucifer fell? And what about love, longing? Everything has to come from somewhere. Why wouldn't he work from something he already knew about?
Now having said all that, is it so hard to believe angels would look down on humans and long for them? To love and want to be with something/one so similar to theirselves but yet just different enough?
A lot of Winged hinges on not just the idea of humans who aren't quite humans anymore fighting demons, but on their interactions with the angels and archangels they meet. There are other themes, but at the end of the day the books come down to one question: what would you do for love?