It is a fascinating subject and as a writer, I also try to flesh out my characters' backgrounds as much as possible in my head. Even when those elements don't end up in the story. I want to disagree with one point Terry made. I don't think Hollywood neglects religion because of deeply held animus. I think Hollywood generally tends to neglect religion because it's a hot button issue that could seriously cut out a segment of your viewership. It's also why characters in TV shows don't express strong political viewpoints, unless it is central to their character. It allows the audience to view those characters through their own lenses. Now, granted, the writer's lens is always going to inform the character, either consciously or unconsciously, but a good writer should be able to write a character whose views and opinions differ from theirs. But I think it certainly helps if the writer really tries to get to know the character's history and past experiences.
For example, I assume Lois is an Episcopalian. I mean, the Lanes are just so stereotypically WASP-y - the alcoholism, the emotional dysfunction, the patronizing perfectionism
. But seriously, it is only in the last few decades that the old class/religion affiliations in the US have broken down. In the 60s and 70s, it was still very much the case that the well to do class was largely Episcopalian, especially in the Northeast. Episcopalianism was the religion of the Northeast elites. Thirteen of our 43 presidents were Episcopalians - the most well represented denomination, followed by Presbyterian at 11.
Lois's hobbies (including chess), the sports she plays (tennis and golf), her music preferences (jazz), her father's profession (a doctor), and her mother's obsession with status all point to the Lanes being well to do, not middle class. We know the Lanes attended church (unless Sam Lane got caught kissing Mrs. Belcanto in the church parking lot for some other reason) and I think to them, attending the right church would be just as important as belonging to the right club and sending their children to the right schools.
I don't see the Lanes as being particularly devout, but there are plenty of members of every faith who aren't particularly devout, so I don't think that tells us much about what Lois's particular faith is. I know plenty of a la carte Catholics and some very devout Episcopalians who attend church every Sunday and really judge every one of their actions by whether or not it advances their purpose of doing God's will on Earth. That being said, the Episcopalian church is more comfortable with doctrinal pluralism than many other faiths, so even if Lois were devout, I don't think that her failure to adhere to all of the tenets of her faith strictly would trouble her as much as it would a devout Catholic.
They gave us a lot of absolute gems when it comes to the Kents' history. We know that despite being from a segregated state (though not as rigidly segregated as the deep south), Jonathan and Martha marched for civil rights. We know that Jonathan told Martha's mother to "stuff a sock in it," and it apparently caused Martha to fall in love with Jonathan in the first place. We also know that Martha doesn't just march to the beat of her own drummer, she pretty much makes her own drums. No matter what religion Clark was brought up with, the Kents doubtlessly instilled in him not only a strong sense of doing what's right, even when it's not popular, but also doing what is right for him, even when it isn't always the expected or traditional thing to do.
I agree with Terry that church is an integral part of life in small towns and think that Methodism, which is often cited as the religion Clark was brought up with, makes sense given the geography and timing. I also agree that the Kents probably withdrew a bit from church when Clark began developing his powers (in order to protect him from discovery), but they wouldn't have stopped going entirely.
I tend to see Clark as a 'seeker.' His very existence isn't well explained or even accepted by most traditional faiths, at least not explicitly so. He's traveled the world and has seen a lot of what others believe and what they have faith in, so I assume that whatever Clark believes, he's not terribly dogmatic about it. He probably believes that there is a lot of value and a lot that can be learned from other people and their ways of life.
I really dislike the 'Superman as Savior' motif and Jor El loving the world so much that he sent it his only begotten son, nonsense. Jor El sent Kal El to Earth in order to save his only begotten son from Krypton's fate. What makes Clark's story so compelling isn't that he was destined to save mankind, but that he chooses to use his powers to help his fellow man. He could be selfish with them, or just keep his head down and try to fit in, but he chooses the burden of being Superman.
All this being said, this is just the backstory I give the characters. None of it is canonical and I'm sure other writers have given the characters their own backstory. I mean, I find it tremendously helpful to think about the experiences that I imagine shaped the characters when trying to figure out how they would react to particular situations, I'm sure others do as well. I don't just apply this to Clark and Lois, but to characters like Perry and Clark's parents as well. I assume that Martha is a transplant to Kansas (at a very young age) from Boston, that her mother never adjusted to or appreciated small town life and was thus never really impressed with Jonathan and couldn't stand the thought of her daughter dating a simple farmer (leading to the 'stuff a sock in it' remark that caused Martha to love Jonathan in the first place). I also assume that it was rebelling against her mother that gave Martha the same sort of stubborn independent streak that Lois has. I think of Jonathan's ancestors as having been Free Soil Republicans who settled Kansas back in the 1850s. I've also written that he had two older brothers, both of whom had passed away fairly young. These backstories - the family histories, the events in the characters own lives, the places where they've grown up and lived, as well as their religious backgrounds, all go into making them who they are, even when they aren't explicitly stated in stories. I would actually find it very hard to write these characters without thinking about all of this backstory.
