Before he ascended into Heaven, Jesus spent forty days with his disciples teaching them about the Kingdom of God.
A short time later Peter had an opportunity to share the gospel with a large group of Jews. Here is what he said. It gives us a glimpse of Jesus' pre-ascension instructions to Peter.
“Repent therefore, and turn back, that your sins may be blotted out, that times of refreshing may come from the presence of the Lord, and that he may send the Christ appointed for you, Jesus, whom heaven must receive until the time for restoring all the things about which God spoke by the mouth of his holy prophets long ago" (Acts 3:19–21).
"Heaven must receive Jesus until the time for restoring all things." What did Peter mean by that? Here is what he meant. Christ's second coming will mean a "restoration" of "all things" (the cosmos) back to its pre-fall condition. That means immortality––specifically no death, no sickness, no aging, or physical deterioration. It means universal holiness––specifically a new world populated by Saints with resurrection bodies, unable to sin, filled with the love of God, eager to pour out their lives in service for each other, unable to experience self pity, ungratefulness, or self-absorption.
Most importantly, it means an eternity spent in the immediate presence of God. We shall see him face to face (Rev 22:4).
For the sick, the depressed, the aged, the marginalized, the worried, those battling with internal sin, this is the best "News" anyone could possibly hear. This is what Paul anticipated when he wrote, “For I consider that the sufferings of this present time are not worth comparing with the glory that is to be revealed to us. For the creation waits with eager longing for the revealing of the sons of God" (Romans 8:18–19).