How do we know Jesus is the spirit of prophecy?

In Revelation 19:10, it states that the testimony of Jesus is the spirit of prophecy. This indicates that the entire purpose of the prophetic texts is to bear witness to Christ's coming and His work of salvation. From the Old Testament prophecies to the New Testament writings, the consistent message is the revelation of Jesus as the fulfillment of God's promises. The prophets were moved by the Holy Spirit to speak of Christ, establishing Him as the focal point of scripture. Without Christ, the Bible loses its meaning and purpose, affirming that He indeed is the spirit of prophecy.