First of all, sorry about what follows, and for my poor english, and for myself too. Yes, it can be called a (good or bad) piece of science-fiction. And also yes, I'm completely crazy and agnostic.
You guys have all common and very well developed concepts of faith. You all are calling it by a name "faith". I've found that faith (with other names too) is something common in almost ALL religions, even pagan ones. With other names, or highly but just conceptually definitions, all the world is calling faith in many many different ways, but referring to the same thing. So for now, I'll use that word, and remember, I'll not refer to faith as what you know for faith, I'll use it just as a word to resemble something in common, but with a different approach.
Now, I always try to speak with examples, but it can be more large than what I'm planning for this post, so I'll try something different here, try to read twice and understand very deeply what I'm about to say, if you have the time, of course.
Let's go on facts first. As
Kêthêrîc wrote in one of his posts, lots of precise physic phenomena needs to be -exact- to make (this) life possible. I can resume all of those in a simple result of one big constant, which is gravity. It may be hard to understand, but imagine that all mass of the universe matter didn't had that relative property or (incorrectly named) force called gravity. None of this would be possible. If you all want to find the responsible of humankind, blame gravity. I can go deeper on this, but is common sense that like the tangents of a spiral that match the lines of outer rectangles in a drawing, "Chaos, sometimes, somewhere, gets straight", it wouldn't be called chaos if that didn't happened.
Next, the evolved world is using today faith as an excuse to believe in something. This isn't wrong, but what faith is, in other cultures, and was ages ago, a slightly different thing. Some examples vary from witches to oriental cultures in where the people used "their faith" to make certain things happen.
As of today, I've experimented myself, and others that I know too (which beliefs differ strongly of what I believe), this kind of "power" that others blamed to a sort of faith (in theirs respective definitions). I saw people cured of (science)deadly conditions, just by making good use of this force they call faith. And also I saw people greatly injured by the "bad" use of this "kind of" power.
It doesn't happen usually that if you believe that something will go wrong, it does go wrong, and if you believe the opposite, it goes well? That's is what I call an example of "untrained" faith. Faith, for me, and the way I *saw* faith -working- is more like "power", power to do something that cannot be done following rules or cannot be possible from a (nowadays) scientific point view.
But what about gravity then? It happens that I do think that the big bang theory is right, but also is the big crunch. It happens that I find very simple the existence of the universe. If I had to put this in understandable words, the whole universe is like God. It always existed, and by his own force (of gravity) created all these galaxies and planets. The gravity of all the matter (and that matter of course) of the universe concentrated in only one point lend it to explode (by simple unstability) and the same gravity will make the whole universe contract and concentrate in that same point again, and again it will explode creating (again) the universe. Speaking of, the only other factor needed for this to happen, is the exact amount of matter in the universe, combined with gravity, makes this big bang happen.
Now after that "metaphysical" view of faith, or power, where does these things converge?. In tiny bits. Living things among lot of different types of matter, are made also, of energy. Call them electrons for now, but going deeper also, it's still matter, of the same universe, matter that these living animals cells control to process other matter, to keep living, to keep renewing themselves, to keep the energy flowing.
My reasoning is that more complex intelligence, as they evolve, may also be able to control this process, not only at the cells or chemical or molecular level, but also at the "thinking about it" level, the Brain level. What I do think of our "faith power" (I still haven't found the right name, sorry ;+) is that it is our "untrained", "neanderthal", and "grotesque" form of -control- over energy in our own universe.
Even each religion, cult, or anything related to faith, may be some way of training our "faith". So mighty power in trying to make something happen, from way many people, may lend (another of my -words-) miracles to happen. This is why I find that religions aren't that bad, if theirs objectives are only to train and empower your faith.
It happens too, that having faith or not having it, in my reasoning, can be good or bad (depends on your point of view) at the time of death. I believe that someone with (somehow) better trained faith can have an afterlife, but someone without faith at all (or without that power trained enough) can't have -any- afterlife. Somehow like what
Killfile said almost at the end of his post about Pascale's Gambit.
Now the following can -surely- be called science fiction.
It's all about imagination (a good old way to exercise faith maybe? controlling energy with your mind to make images get to your "visual processing unit" in your brain? sorry, back

).
Imagine that when you die, the energy that your cells where processing and your mind trying to control is out of the body, free of any bounds or chains to anything. But you in life managed to (actually barely) control this kind of energy, now all of you left is -that-.
Imagine that with good control of it, you can become something else in the afterlife (only limit is your imagination here). Now (for the bad side) imagine that without control, without trained faith, when you die, your energy just disperses and comes back to where it came from (the universe?). This is what I think of Heaven (only limit is your imagination) and Hell (disperses around).
To finalize this explanation, I'll just add that this reasoning about life itself came from science and faith (this time the way u all know both of these). And transmuted, more or less, in what I just wrote. Also something about faith is true (again depending on your imagination) that's the only way to "salvation" ;+).
Again, sorry for the big post, It may be my lack of english that sometimes I can't find the right words and switch to some fallbacks.