In John 1:1, John writes, seemingly breathlessly, of “that which was from the beginning,” the “Word of Life,” who is the Eternal Son. John says that he himself heard Him, saw Him with his eyes, touched Him with his hands. This is God-in-Flesh, God made manifest, God made tangible. And it is this life which John says he proclaims to us.
It’s no surprise, then, to find John, who ecstatically writes of the Son of God whom he heard, saw, and touched, proclaiming this Jesus to the rulers of Israel and telling them “we cannot but speak of what we have seen and heard.” (Acts 4:20)