There's a local park/pond that graces a particularly busy intersection here in town. It's kind of the unofficial center of the town; the place by which you can locate yourself with respect to anything else around here. On the lawn, during the Christmas season, a number of displays were erected to celebrate the impending holidays of various groups: a gaudy Christmas tree, a Jewish display with a menorah, and a large display from the local atheist club, who describe themselves thus, "A group that provides support, outreach, meaningful discussion, opportunities for activism, friendship, and fun for fellow atheists." The display read, "Our hope for the holidays: peace on Earth."
Now, first of all, I'd like to thank the local atheist group for their kind, timely message. Many other secular/atheist organizations have been plastering the public space with deliberately provocative messages that do little more, I imagine, than let these folks feel really satisfied with themselves and offend the people that they take to be idiots. Not this local atheist group. They decided to be kind and offer well-wishes of peace on Earth, a sentiment with which I whole-heartedly agree (after all, I follow its Prince)! Especially during a time that can be so chaotic and self-centered, the desire for peace is a lovely standout.
I wonder, though, whether the desire for peace can really be explained or justified on an atheist worldview. I suspect that it cannot. When the atheist expresses a desire for peace on Earth, he is, on his worldview, merely stating his preference. But he isn't giving us any reason why we ought to share it. He can say that he desires peace on Earth, but he can't give me a reason that I should desire it. To hope for peace on Earth is very much like having hope for root beer with lunch.
Allow me to put it a bit differently. On atheism, peace on Earth isn't, in any objective way, better than mayhem on Earth. And any of the obvious reasons (with which I agree, by the way) are insufficient. "But mayhem causes pain and misery and suffering." That's true. It sure does. But if atheism is true, then so-the-heck what? There exists no objective moral law that mayhem would violate. Those who cause mayhem face no ultimate justice. They just get the spoils of their mayhem, whatever they are, in the here and now. Why should such people prefer peace to mayhem, when mayhem pays the bills? In fact, that's how some people operate, like the Mafia or the Hell's Angels. They live not for peace, but for the spoils of mayhem.
To be sure, we all know that the thugs are wrong. And that what they do is wrong. It's so obvious that it's almost impossible to believe otherwise.
Statements of ultimate, however, objective value are off limits to the atheist. He must borrow from the theistic worldview in order to use them. On his own, without the help of God, his statements about what is good or better or worse are nonsense. They express nothing more than his local preferences. "Peace is superior to mayhem" has no more existential heft than "chocolate ice cream is superior to vanilla ice cream."
Sure, friend - - you prefer peace to mayhem. I do, too. But I can tell you why it is better; you can only say why it's different.