This post might be bothersome to those that are still heavily religious, as I am pondering on the possibility of moral relativity. If that is problematic for you, don't keep reading.
First, I am really annoyed by the assumptions people make when I tell them that I don't consider myself to be Mormon anymore. Mormons will immediately jump to the conclusion that I am sinning and trying to justify my behavior. I find this highly unfair, but not nearly as unfair as the next jump they make if they determine that you aren't sinning. They automatically assume that you are doing things the "right way." That you are not praying right, or reading the scriptures correctly, or going to church with the wrong attitude, or whatever. Failing this argument, they jump to the conclusion that you must have been offended by someone. What gets really entertaining is when this argument fails. The next jump is completely unpredictable, from "I don't know" all the way to "you must be psychologically unstable." Why can't they just let people have their own freedom to choose?
That aside, I want to talk more about "sinning" and morality. The assumption that I "left to sin" is simply absurd. Sure, maybe there are people like that. I am not one of them. I left because I could no longer consider the church to be true. There was no way for me to reconcile what I was hearing and learning about in the church with what I was feeling and understanding to be true. That being said, I am not still living the "Mormon lifestyle." Mormons, however, get the causal relationship all wrong. I didn't leave to do what I want, I started doing what I want after I left.
The notion of sin is an interesting one. As such, morality and sinfulness are all described more or less in the context of a religious belief system. Without such a system of beliefs, the reasoning behind behavior changes completely. This does not imply a hedonistic lifestyle at all. Look at things from a more scientific perspective. Hedonism will not keep an organism happy, it leads to an out of balance life, and will rack up problems more quickly than it will pleasure. You need to work altruistic notions into your model before a good behavioral model will arise. Why would you work these notions in? The most succinct reason I can put (you should be able to extrapolate from here and come up with more of your own reasons) is that you won't stay happy long if you keep pissing people off. If you keep others happy (to a healthy degree) then they will help to keep you happy. This is, in essence, the way that we learn to cooperate, even in extremely selfish societies. If you want to learn more about that concept, I recommend the book The evolution of cooperation by Axelrod.
With that in mind, how do I then determine what is "right" and "wrong" behavior? It has now become an extremely loose concept, and I can see why this makes many people extremely uncomfortable when they find themselves in a similar situation. Perhaps there isn't really an absolute right or wrong, but situation rights and wrongs. We need to evaluate in any given situation what should be done. We can try and rely on magical thinking or higher powers all we want, but I don't think that any intelligent deity would want to create a culture of complete dependence, but would rather want to foster independent thought and action. You learn by doing, experience being your master. You learn by recognizing what will cause problems and what will prevent problems, what will make you happy and what will bring you pain. In this sense this makes life a lot more formulaic, but that doesn't necessarily need to be a problem.
Here are some interesting questions in the context of Mormon morality. What makes a person inherently more evil for drinking coffee, tea, or alcohol? And yet, they consistently treat people poorly for such actions. What makes a person inherently more evil for masturbation, fornication, or homosexuality? Why is it that once sexuality is involved, all of the sudden everything not completely controlled by the church is evil? Am I going to start trying to destroy humanity simply because I have a sip of coffee or tea? Or will it take something "extreme" like not paying tithing or attending church before I will try to destroy others? Maybe those aren't sinful enough, maybe I have to be so bad as to go to a grocery store on Sunday, or say no to the church to spend more time with my family? For all of these heinous crimes and more the church will question and belittle you, in addition to denying you the "blessings" in the church. So, I am only good if I am completely obedient? Since when is that a virtue? Should we be teaching children to obey everyone without question? Why? It is a virtue, isn't it?
I would submit that all of this "sinful" behavior only becomes bad when it starts to hurt others or hurt yourself. There is no need to dictate behavior that doesn't cause any problems for anyone. There is no need to cause an uproar over simple issues of preference. These are some of the things that caused me to have an issue with the church in the first place. It is not their place to tell people to do in half of the instances that they choose to do so.