The goal from the beginning was for all mankind to share in the eternal life of God (i.e., the divine life) and this is what is restored to us in Israel’s Messiah King, Jesus.
What’s the issue? John says it clearly: “There is one among you whom you do not recognize.” At this point in the story, Jesus is already there, walking among them, but no one recognizes him—no one recognizes that the one they have been waiting for has arrived.
We don’t like thinking about Jesus’ return. We’ve heard a lot of scary things, judgmental things, fire and brimstone things about the “Day” that Jesus returns. So what gives? Is this “Day” that is coming a cause of fear or is it good news?
Advent hope stems from Christmas: God who is faithful to his promises came once, and so we have hope that he will come again. That is our great hope: our great hope is that the Lord Jesus Christ will come again to completely establish his eternal Kingdom on earth as in heaven, for which his first coming opened the Way and his second coming will bring to completion.