The sun rose. The sun set. God finished off a few buckets of popcorn and decided it was about time to send his Son to get folks back on the right path. Sadly, it wasn’t long before folks wandered off the path again.
Even in the New Millennium with no war, abundant prosperity and the world resorted to Pre fall conditions, people will be still be prone to wandering off the path. That’s why He will rule the nations with a “ rod of iron”. And many people will not like it, being unredeemed but living outwardly righteous.