"I, Jesus, have sent my angel to give you this testimony for the churches. I am the Root and the Offspring of David, and the bright Morning Star." (Revelation 22.16)✞
Jesus guaranteed the truth of all that John had seen and heard to everyone. This applied to all committed Christians as indicated by the first person plural "you." In Liverpool where I came from they would say that the plural of you was "yous." The point of the guarantee is this. The book began in Revelation 1.1 by promising a revelation to be given by Jesus. This was the statement by Jesus and the substance of the vision.
Jesus then went on to give, as it were, his credentials. "I am the root and offspring of David," he said. This was probably a reference to Isaiah 11.1, "A shoot will come up from the stump of Jesse; from his roots a branch will bear fruit." Jesus was saying that in himself was the fulfillment of this prophecy and he was the shoot growing from the stump of Jesse. He was at one with God and the same time the eternal source of being from which Jesse, David and his promised descendant came. Jesus also then stated that he was the bright morning star.✞