One answer to his rhetorical question is this. Christian theology has proposed and articulated a vision of reality that is more essentially personal than it is material. It has therefore accredited human persons with a very high dignity indeed.
Consequently, it has provided reasons and motives for the likes of Francis of Assisi, Albert Schweitzer and Mother Teresa to devote their lives to the service of the well-being of their fellow humans.
Christianity has also, for example, provided severe moral constraints upon (medical) scientists who, through inordinate curiosity, lust for professional advancement, or utilitarian motives, have been tempted to treat their human subjects as means and not ends.