If you go to the second floor of the National Museum of American History in Washington, D.C., you’ll find a small room containing an 18th-century Bible whose pages are full of holes. They are carefully razor-cut empty spaces, so this was not an act of vandalism. It was, rather, a project begun by Thomas Jefferson when he was a mere 27 years old. Painstakingly removing those passages he thought reflected the actual teachings of Jesus of Nazareth, Jefferson literally cut and pasted them into a slimmer, different New Testament, and left behind the remnants (all on display until July 15). What did he edit out? He told us: “We must reduce our volume to the simple evangelists, select, even from them, the very words only of Jesus.” He removed what he felt were the...