I really like Thomas Sowell. He is not a Christian. I wish he was. He does not use the Bible as the basis for his logically consistent ethical argument; but he has a great mind and a great sense of the inconsistency of the liberal worldview. He is a prolific writer and outstanding economist. His book Marxism: Philosophy and Economics is extremely helpful, as is his Quest for Cosmic Justice. Most recently he has written The Housing Boom and Bust and Intellectuals and Society. Tim Challies has a review of Intellectuals and Society here. If you have not read any of his works, you can check out some of his shorter articles at Town Hall. His most recent article on Tiger Woods' apology is fascinating. You can read it here.