I've been thinking about this one for a long time. Having been raised Catholic, I was taught at an early age to try to live Christ's example and eventually lead by example. While I have slowly, philosophically descended into the seventh circle of hell with regards to my specific faith and beliefs, there was always something powerful about that teaching. (We could argue the specifics of what "Christ's example" means, but most people who were raised and/or are practicing Christians have at least some vague idea of what I mean.) In philosophical wanderings, though, on this topic, I always found myself coupling this set of rules with another set: let he who is without sin throw the first stone and, when asked what to do about someone who has just injured you, we are asked to show that person the other cheek.
In all four of these powerful messages, though, I don't hear any talk of force. There is a subtle live and let live undercurrent. I may choose to live through the example of others, but in the case of judgment and/or acting upon someone's misdeeds, we are taught to accept and move on. In many ways, we are asked to not react.
I think there are many atheist, non-Christian, evolutionary, and materialist arguments that could be made for managing ones actions in a similar manner. Some day, I hope to be able to delve into some of those for which I believe I have a relatively firm logical grasp. But for now, it seems to me that one of the messages one can learn from above is that it would, in fact, be immoral to impose one's manner of thought and action upon another. The consequences of this conclusion are innumerable. At the end of the day, this means you must be committed to letting people act in a manner you find reprehensible. To clarify, no sensible person would advocate that this means indiscriminate violence against others should be allowed or condoned. It means, though, that actions committed/taken within a private sphere shall not be judged - and it would even be wrong to act as if you had a right to do so. For if we are supposed to live by Christ's example, point to me the scripture that states He advocated taking control over another's life because you believe you know better. If we determine much of our morality by that of general Christian values, then doesn't it mean doing so would be immoral?
By the way, if you're an atheist, the argument becomes even cleaner, because it is not necessarily subject to wide interpretation. Coercion deprives a person of the very thing everyone, every man, woman, and child, holds dear at some point: individuality and the ability to act in one's own best interest. Depriving someone of this one thing is the tipping of the first domino that sweeps personal freedom and autonomy into a wasteland of dependence and loathing.
Either way you dice it, the axiom should be: choose for yourself, not someone else.
