Christians, we are often told, are easy to locate. They are the people marooned on the wrong side of history. Again and again, century after dispiriting century, they have dug in their heels against progress. In politics, the critics charge, a Christian's instinctive allegiance has been with despots and oppressors rather than democrats and liberators, with inquisitors and book burners as opposed to probing minds and pamphleteers. Christians have buttressed hierarchy against equality, patriarchy against women's rights, absolutism against individualism, and small-minded tradition against broad-minded tolerance. The most popular version of this indictment sees the whole of Western history since...