ACTS 1.6-8: So when they had come together, they asked him, “Lord, will you at this time restore the kingdom to Israel?” (7) He said to them, “It is not for you to know times or seasons that the Father has fixed by his own authority. (8) But you will receive power when the Holy Spirit has come upon you, and you will be my witnesses in Jerusalem and in all Judea and Samaria, and to the end of the earth.” (ESV)
The question the disciples asked of Jesus in verse 6 indicates that they did not have a full understanding of the purpose for which Jesus gave his life on the cross and was raised from the dead. At a minimum, the question shows that their sense of priority was not in keeping with the priority of Jesus. In the years preceding the life of Jesus on earth, the common and most likely prevailing understanding among the people of Israel was that the Messiah would liberate them from the oppression of the Roman Empire. This was a faulty idea of the mission of Jesus.
Jesus was not born and crucified and raised from the dead for the express purpose of liberating the people of Israel from the subjugation of the Roman government. The purpose of Jesus was to be the sinless, perfect sacrifice to take away our sin and to establish God’s New Covenant, thus becoming the Mediator between God the Father and us. In the Book of Revelation Jesus is referred to as the “King of Kings”. And the kingdom that Jesus established was and is His own Kingdom.
But answering this question of the disciples was not Jesus’ most important priority at that moment. Jesus was getting ready to ascend into heaven, and in verse 8 He communicated to the disciples the mission He established for them to carry out. And He affirmed to them the means by which they would do so. The mission is global. It was beyond their human capacity, and it is beyond our human capacity to carry out.
I believe the New Testament teaches that when Jesus returns to earth He will establish His kingdom in Jerusalem. And it is at that time all things will be restored. But before that, Jesus has given the mandate which pertains to all believers in Him. Namely, to be witnesses of Him. Witnesses of the salvation and forgiveness of sin He offers to all who will put their trust in Him.