“Beyond all question, the mystery from which true godliness springs is great: He appeared in the flesh, was vindicated by the Spirit, was seen by angels, was preached among the nations, was believed on in the world, was taken up in glory” (1 Timothy 3:16).
The ascension is Christ’s return to heaven from earth.
Almost all NT letters contain a reference to the exaltation of Christ after His resurrection. The Book of Acts describes in some detail His departure.
The book of Acts is a book about Jesus…Him in a different way…in a way that He is present everywhere the apostles go: Jesus through the church (empowered by God’s Spirit) continuing His work in the world.
The 11 apostles were witnesses of Jesus’ ministry; suffering and death; resurrection and ascension.
One stubborn thought surfaced more than once in their minds. “We are getting the idea of God’s kingdom…we would like to know “WHEN” it is going to come, roughly, please?”
“…the disciples came to him privately. “Tell us,” they said, “when will this happen, and what will be the sign of your coming and of the end of the age?” (Matthew 24:3). “Tell us, when will these things happen? And what will be the sign that they are all about to be fulfilled?” (Mark 13:4).
Jesus clarified for them (and for us) that being a follower of the risen Christ is NOT a matter of knowledge of times and seasons – versatile in knowing the future in detail (Acts 1:7).
Being a follower of the risen Christ IS a matter of being empowered by the Holy Spirit to be His witness anywhere on this earth (Acts 1:8).
Why did Jesus have to go that way? Why ascension at all?
Let me put it this way: earth is no place for a heavenly body like Jesus had after the resurrection. We cannot live forever on a planet/earth (Romans 8:21) that will not last forever! He will come back at the renewal of all things – renewed to last forever! Until then He is the heavenly Mediator!