From our perspective the start of God's Kingdom is our end destination. It's like the end all goal. But there's probably way more beyond that than we could comprehend now. To Jah, once all this is behind us, that's when he can finally carry out his original purpose. None of this was ever supposed to happen. Had Adam and Eve never sinned God could have revealed much more to humanity than he could with us. Maybe the tree of the knowledge of good and evil had a purpose beyond just testing humans. There could have been a whole other chapter to that story that God wasn't able to get to. Since humans failed that initial phase, his plans were put on hold. Our loose understanding of events lead up to just after the reign of Christ. We have no idea what comes after that. 1,000 years really isn't that long, especially when weighed against an eternity. I am certain we will still face challenges. They just won't be the same kind of stuff we deal with today. Challenges aren't always bad.
So really, right after the Bible concludes is when God can pick up where he left off. So it's like Earth day 8. We haven't even completed day 7 yet.