Ephesians 1:3-12, Col 1:9-14

It is typical to think of the doctrine of last things, including the messianic kingdom (the kingdom of God/heaven) primarily in terms of timing and events. While these are certainly exciting, key features of the Biblical revelation, they are secondary to the central living Person, work and offices of the Messiah, Jesus, the Son of God, in the plan and pleasure of God the Father:

Col 1:19-20 For it was the Father’s good pleasure for all the fullness to dwell in Him, 20 and through Him to reconcile all things to Himself, having made peace through the blood of His cross; through Him, I say, whether things on earth or things in heaven.