Varied Definitions of Law and Gospel
This post by Peter Leithart shows the current great general gap in meaning for most who use theological terms. They have words, and they use them, but they either do not know or do not care to know how they have been used in the past, or to stick with some commonly agreed-upon meaning. It also demonstrates the great gap between Calvinism and Lutheranism: no Lutheran who has been paying attention would comfortably speak of the “age of the law” and the “age of the gospel”; yet still many Calvinists (though not just Calvinists, though they are the group of Christians I hear using Law and Gospel more than other non-Lutherans) think that we mean the same thing when they use these words. We really don’t.