b) things that are wrong because they prevent you from achieving your goals.
Who decides our goals? If my goal is to live the best life I can using the evidence at hand as a measure of what that means, without any belief in a god whatsoever. Does god judge me based on those goals or on what he considers our goals should be?
What if someone's goal is to kill a string of people and go out in a hail of police gunfire? Does the fact that he sadly meets and exceeds his goals mean he gets a prime position in God's graces?
Would this not require that whoever or whatever created the universe also created morality and the concept of sin as part of that universe? In which case are we not back to the arbitrary nature of sin as designed by some sort of universe creating god entity? I have no idea what mormonsim teaches about the origin of the universe (and thus sin) but if there is a creator involved I think we are necessarily back to arbitrary god-given laws again.
A potential loop-hole is if you assume God is not omnipotent. If he had to make compromises in order to make a stable, life-supporting universe, perhaps the existence of sin is a necessary trade-off. I know this is an unsatisfactory answer for people on both sides of the debate, but it is still a possibility.
Another option, and forgive me if I'm stepping all over Mormon beliefs here, is that if sin is an obstacle to "Godhood", perhaps it is there merely as a test. In school, getting wrong answers lowers your grade, not out of animosity or arbitrariness, but because you didn't have the right answer. The directions may be arbitrary, but perhaps there aren't any that aren't arbitrary, so God has to pick something. He's giving us something to strive for, and not making it too easy.
Of course, if god doesn't exist, then sin doesn't either. So I'm still off the hook.
Thing is, you left out a third option (c) things that are wrong cause they are wrong. Them things are sins.
This implies some sort of objective morality that exists regardless of a god. While this may be possible, it has yet to be shown how we can determine what this objective morality is, and if morality exists regardless of a god, that removes one more reason some theists give for needing a god.
ex. "Without a God, you could do anything you want because there would be no Hell for you to be worried about." This is a fallacious argument, but it is made with regularity, so I felt the need to mention it here.
Life-long Christians who lose their religion almost invariably go through a phase where they are not responsible atheists, but callous nihilists. I go through this periodically myself as I'm dealing with my current confusion over religion, and it can get frightening.
I never used a God as my moral compass (though when I was younger I believed in one vaguely) but in an intro to philosophy class that really opened my eyes (in more ways than one) the prof showed us what she called the Two Pronged Argument regarding God-given morality:
Prong 1) God says "I'm good, thus everything I do/say is good." In this prong, things are good only because God says they are, so he's stacking the deck as it were and defining himself as good. He could just as easily have told us rape and murder is good, so it's all arbitrary.
Prong 2) God says "This is good, so I will command it." This takes morality out of God's hands, and makes it something objective, and thus, we can find it for ourselves without God.
Both of these are the only logical possibilities when a God gives moral commands, and neither of them are scenario actual believers want. They want a sort of middle ground where God is objectively good, but we need him to tell us what to do.
The fact that believers of different religions and nonbelievers alike can behave morally or immorally in generally equal number, it seems to be human controlled more than God controlled. My compass has always been myself and the people I know rather than some book or a vague being I couldn't even see.
I know you're responding to Stile, but I thought of another possibility along these lines.
When I talked about it being an innate part of the universe, I was thinking more along the lines of God being unable to design a universe where sin doesn't exist. Maybe, as you say, it would be better for me to characterize sin as an innate part of intelligence, human nature or spirituality, than as an innate part of the universe itself.
Rather than an innate part of intelligence, it could be an innate part of free will. One of the big doctrines in most Monotheologies is Free Will. If there really are things we need to do in order to make it into whatever Paradise exists, and God wants us to be more than automatons, then we must have the ability to do things contrary to that goal. God would then, perhaps, feel the need to try and convince us to do the right thing because he doesn't want to force us to do so. His way of convincing, whether the most effective or not, is to threaten us.
What if my personal goals are to cause harm to others? Would it remove the sinful nature cause they are my goals?
Read the whole thread. I brought up this very question and Bluejay explained that it's not personal goals, it is the "goal" of Godhood that sin keeps you from. You can choose not to pursue this goal, and that's your choice, but you then won't attain the full glory that is open to you.
Mormonism also holds that there are certain ordinances that need to be performed as part of the process of attaining salvation, so it would be difficult for someone who does not believe in God to achieve godhood. Unfortunately from your standpoint, this basically means you must believe in God: so I suppose you would consider Mormonism to have also failed this test.
If sin is what keeps a person from attaining godhood, and not believing in god is a sin, then it would seem to argue against sin existing independently of god. It would bring it back to arbitrary rules put in place by a jealous god.