What does the Bible say about the eternal nature of Jesus?

In Revelation 1:17-18, Jesus identifies Himself as the First and the Last, affirming His eternal existence. This means that He was present at the beginning of all creation and will remain until the end of time. John emphasizes this truth, speaking to the continuity of Christ's existence and His divine authority over life and death. According to Hebrews 1:2, God has spoken to us through His Son, affirming that Jesus is not only part of our temporal existence but is also integral to eternity itself.