The new Pew Forum report on the size and distribution of the Christian population around the world could give triumphalists reason for high-fiving: Christianity is still No. 1, at least in terms of overall population, with about 2.2 billion adherents, or a third of the global population. And the United States has the most Christians of any country!Islam comes in second, globally, with 1.6 billion. So there.But the Pew report also notes a sobering irony: Christianity in the Middle East, where the faith was born, is all but gone. And Doonesbury today draws our attention to the United States’ role in hastening that decline:H/T: Mark Silk’s “Spiritual Politics” blog.