Dennis Prager has been writing a series of articles entitled "The Case for Judeo-Christian Values" and Part IV is about the fact that the Judeo-Christian worldview provides for humans dignity and worth. He makes a good case and I certainly agree that, pragmatically speaking, Judeo-Christian values are best for the culture. I am sure that Terri Schiavo and Sun Hudson, two people who are today in the hands of public institutions that may deem them not worthy of keeping alive, would agree with them.
Ultimately, though, accepting values for pragmatic reasons is unsustainable. The real question is not which values suit our needs or which values we like the best, but whether or not the worldview underlying those values is true. The culture war will not be won or lost arguing for one set of values over another, but rather by arguing for the truth of one worldview over another. If Christianity or Judaism is true, then life has inherent value. If philosophical naturalism is true, it does not. It’s as simple as that.