How do we know Christ is the central message of the Bible?

The central message of the Bible is Christ, encapsulated in the Gospel. As stated in Philippians 1:16, Paul emphasizes his role in defending the Gospel, which is the proclamation of Jesus Christ as the Savior. This is consistent with the teaching in Acts 4:12, where it's declared that there is no other name under heaven given among men by which we must be saved. The Gospel message that Jesus is the Christ encompasses all that Scripture conveys about redemption and grace. Furthermore, Jesus himself affirms this in Luke 24:27, where it is said He explained to the disciples what was said in all the Scriptures concerning Himself, demonstrating that all Scripture ultimately points to Him.