"What shall we do?" was the question people asked John the Baptist as they came to be baptized. Others asked this question of Jesus during his ministry in Galilee, and of Peter on the Day of Pentecost. After two thousand years, even many confirmed Christians remain confused. May a Christian work on the Sabbath? Is the Sabbath Saturday or Sunday? Must we eat Kosher? Paul said that Christ fulfilled the Law, so what are the rules for today? Must Christians...