Abraham Lincoln was fond of asking, “If you call a dog’s tail a leg, how many legs does a dog have?” “Five,” his audience would invariably answer. “No,” he’d politely respond, “the correct answer is four. Calling a tail a leg does not make it a leg.” Like Lincoln’s associates, many of our fellow citizens—including many Christians—appear to fall for the notion that changing a definition causes a change in essence. A prime example is the attempt to change the definition of marriage to include same-sex unions. Simply calling such relationships “gay marriages,” many believe, will actually make them marriages....