There are a great number of things about which I think I would believe differently if I were not a Christian. (Truthfully, I think it is either a self-deceptive or a worthless sort of faith that says, "I would believe everything I do now whether God affirmed those beliefs or not.") For example, I think if my understanding of the nature of sexuality were not tempered by an understanding of divine intentionality, the practical outworkings of those views would likely lead to some form of sexual libertinism. Similarly, while I think I would still be in some sense be a complimentarian regardless of my faith, I think the nature of that belief would be significantly altered. I certainly would not hold the absolutist views that I do about things like lying and violence, for example, without my faith.
I say all that in order to contrast it with my beliefs about the intrinsic value of self-restraint. One of the hallmarks of Christianity (a hallmark, not a foundation - I clarify knowing that I have officially spent too much time immersed in Protestant scholasticism) is the ability of the will to restrain the corrupt impulses of our nature. For Paul this is expressed in terms of a constant battle between the spirit and the flesh, a fight against the will of his members in which he is perpetually engaged. For Paul, as well as thousands of early Christians there was the additional application: the will must restrain natural fear of death in order to stand up to martyrdom. When martyrdom was no longer a threat, Christianity expressed this most noble of its aspects through rigorous asceticism. Today, though the corporate state of Christianity is one more interested in utilizing the will to restrict the flesh of others, the ability of the will to restrain the impulses of the flesh is still an essential character of the greatest men and women of faith I have ever known.
Yet, I think that this particular virtue is so consistent with what I believe to be right that I would extol it regardless of my faith in Christ. The ability of someone to be in complete control of his person would be the most impressive achievement I think man could ever accomplish. This is not a matter of simple self-control, since that says nothing of the aims of the person in control. (After all, imagine if Hitler had always been in complete control of his person, how much more potent a force he might have been.) This is not the ability of man to restrain himself to reach his own ends, but the ability of man to restrain his own desire for those ends in favor of some other ends. This is truly virtuous apart from God (if that were in fact possible), as it signifies man's transcendence of himself. What, after all, could be greater that, since by its definition self-transcendence necessitates that a man becomes better than himself?