This was in my local paper a couple of days ago.
Found here. A good explanation.
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New Testament prophecy has its roots in Old Testament prophetic ministry. In the Old Testament, God raised up certain individuals to be His mouthpiece and speak His heart and mind to the people of Israel. These individuals were known by the Hebrew word nabi, which the Greek Septuagint translated as prophetes, and our English Bibles translates as "prophet."
They were not fortunetellers. Their purpose was not to satisfy human curiosity to know the future. Their purpose was to speak the heart and mind of God to the people. In carrying out their assignments of speaking God's word, their prophecies at times revealed future events, but that was not their purpose.
The nabi did not choose this prophetic vocation, but it was given to them by God. This is obvious in the answer of Amos to King Amaziah, who had ordered him out of Bethel and commanded him to never prophesy there again. To emphasize that his prophetic calling was not of his own choosing, Amos replied: "I am no prophet, and I am no prophet's disciple. Rather, I am a herdsman and a dresser of sycamore trees. But the Lord took me away from the flock, and the Lord said to me, 'Go, prophesy to My people Israel'" (Amos 7:14-15).
Not only did the prophet or prophetess not choose their calling or vocation, neither did they choose the messages they were to deliver. The messages came to them spontaneously according to God's determination. This is obvious from statements such as "the Spirit of the Lord came upon " (2 Chron. 15:1; Isa. 61:1), "the hand of the Lord was upon" (Ezek. 3:14, 22; 8:1; 33:22; 37:1) and "the word of the Lord came" (1 Sam. 15:10; 2 Sam. 24:11; Hag. 1:1), all indicating the onset of the prophetic message apart from the initiative of the person prophesying.
In the Old Testament, the prophetic vocation was very limited, but with the coming of Messiah Jesus and the outpouring of the Holy Spirit, the Old Testament prophetic franchise, instead of being ended, was expanded to include all of God's people. In this new and better covenant, the gift of prophecy is available, at least potentially, to all of God's people.




