We interpret much of the Old Testament in light of the New Testament, but the keys to the signs and symbols of the book of The Revelation of Jesus Christ are found in the Old Testament. This is where we discover the message of the seventh trumpet. It will sound along with the previous six trumpets on the last day, but the Lord has been sounding this message throughout all of history. The trumpet symbolizes the direct voice of God and the gospel of redemption. It was blown to warn of danger and announce that there is shelter and protection in God.