Difference b/w covenant and prophecy?

Covenant is a promise or a contract. Prophecy is the proclaiming or foretelling of God word. Today's preachers however are not prophets in that sense- the preacher today proclaims the good news of the gospel. The old covenant was the promise of the messiah, the new covenant is the fulfillment of the old and sealed by the blood of Jesus. The promise of eternal life in Heaven.