QUESTION: In Acts 15:21 there were those who preached Moses in the synagogues every Sabbath. Why did they not preach Christ?
ANSWER: James is not talking about Christians in this verse, but is talking about those unconverted Jews who were still keeping the Law of Moses. To preach Christ (Philippians 1:15-16) is to preach the Law of Christ; the New Testament! When the Jews preached Moses, they preached the Law of Moses; the Old Testament.