Prophetic ministry, as charismatic groups understand it today, is any ministry that relies on the gift of prophecy and new revelation from God to lead the church to maturity. Those involved in prophetic ministry sometimes refer to it as a fivefold ministry and believe that the offices of apostle and prophet are being restored in the modern church.
We often see the prophetic ministry in the Old Testament, when God raised up prophets to encourage and rebuke the nation of Israel in times of trouble or rebellion. During the reign of King David (2 Samuel), the prophet Nathan, among others, spoke the word of the Lord to David, to guide and direct him, and likewise to confront him about his sin with Bathsheba. Of course, Isaiah, Jeremiah, Hosea, Amos, Micah, Zechariah, etc., also had a prophetic ministry; after all they were prophets. The calling of a prophet was to speak on behalf of God. A prophet taught, guided, counseled or rebuked if necessary.