The gift of prophecy builds up God’s people, but should not be mistaken for the ministry gift of the prophet. We prophesy in the gift according to the proportion of our faith (Romans 12:6).
Small faith is revealed in shallow, general prophecies. Nothing wrong with that; we need to start with the faith that we have. Greater faith is revealed in deeper, more specific prophecies.
As to the ministry gift, over the years, I’ve encountered authentic prophets, and the difference between the ministry gift, which God has set in the church, and the spiritual gift of prophecy, which the Holy Spirit gives to many in the church, becomes clear when the prophet speaks. There’s an overriding authority in the message delivered by the prophet.
How then to become a prophet, a ministry gift to the church? Only the Lord can present you as that gift to the church. I suggest that you begin in the gift of prophecy and begin to build up, stir up and cheer up God’s people. As your faith grows, your prophecies will become more specific.
The same applies to the other ministry gifts of Ephesians 4:11, who likely began with a spiritual gift and in time became a ministry gift. Just as it is the Holy Spirit’s prerogative to distribute spiritual gifts according to his will, it is the prerogative of Jesus to place certain people in the church to train people for the work of ministry.
Every believer is called to a ministry of some sort — Chapter 12 of Romans makes this clear. I hear people prophesying that certain nations are about to experience the Lord’s blessing, but if the prophecies are general rather than specific, I don’t mistake these people for prophets. However, I can tell you that if you ever encounter a real prophet, you’ll come away knowing the difference!
Christians who see their primary purpose as sharing the Good News of Jesus Christ to whoever they can wherever they are, may develop to the degree that they become evangelists. So it is with others whom the Spirit of God has given spiritual gifts. This is but one example of how a gift can work so well in one who prophesies that they are seen as ministry gifts; i.e. the spiritual gift is so one with the person who prophesies that he or she is identified with the ministry gift.