Preaching

 Perhaps a good way to think of a "prophet" in the Old Testament is a 'preacher.' Many generally think of "prophecy" as having a predictive element. This can be true, but when God's word is preached to people who are living in a sinful world, it is relatively easy to predict that corrective events will occur at some point. So long as the preacher shares the Word of God, he is following the guidance of the Holy Spirit. "For prophecy never had its origin in the will of man, but men spoke from God as they were carried along by the Holy Spirit." 2Peter 1:21 (NIV)