The apostles, who had just spent 40 days talking to the risen Lord about things concerning the Kingdom of God (Acts 1:3), raised a question that probably grew out of those discussions:
Lord, is it at this time you will restore the kingdom to Israel?
O. Palmer Robertson, in his interesting book, The Israel of God, suggests that the answer to that three-fold question is found in vv. 7, 8:
It isn’t for you to know the times or seasons that the Father has set by His own authority; instead, you will receive power when the Holy Spirit has come upon you, and you will be witnesses in Jerusalem, in the rest of Judea and Samaria, and to the ends of the earth.
To the first part of their question—when will the “restoration” occur—Jesus told them that God wasn’t about to tell them. To the second part of the question he replied that the restoration would be of such a nature that it would involve the coming of the Holy Spirit upon them in power (in other words, it would be a fulfillment of the Abrahamic promise that would institute a wholly new phase of Israel’s existence), and in answer to the third part—Israel, from henceforth, would include Gentiles from all over the earth where they would be sent to preach the Good News.
This is, of course, a different thought than many have in reading the verses in view, but it seems consistent contextually with what actually was said in response to the inquiry of the curious disciples.
Doubtless, the new “nation” (called the “Israel of God” in Galatians 6:16) predicted by Jesus in Matthew 21:43, that would replace the political Israel of old, would be (as Jesus said in John 19:36) not “from this world.” If it were, He said, then, there would be physical action taken to prevent His capture. His Kingdom was a kingdom of truth as He told Pilate. Rather than a continuation of the old order, this New Spiritual Israel was to be what Peter referred to as “a chosen race, a kingly priesthood, a holy nation, a people who belong to Someone . . . a people who at one time were not a people” (I Peter 1:9, 10). So, the new Israel—now carrying many of the older titles—would be Israel “restored” as a reconstituted body that exemplified individually in the lives of its members, those things that were always signified by the external’ sacrificial system with its types and shadows. The “reality” had come at last. This “restoration” was a restoration in terms consonant with the fulfillment of the Abrahamic promise that his Seed would become a blessing to all the nations of the world. Consequently, the church of Jesus Christ has been carrying on that task ever since Pentecost.
He is a Jew who is one inwardly; he is not a Jew who is one only outwardly. Do you belong to the new Israel, restored as a kingdom of prophets and priests, as the body of Christ, as His bride, and the building housing the Holy Spirit? If this is all confusing, read Robertson’s book, but of even greater importance, be sure to read and believe the Gospel of Jesus Christ by which, alone, you may be saved. He died in the place of guilty sinners like you, and (on what we call Easter) rose from the dead. He ascended to the throne of God where, today, as co-regent with the Father, He rules this new, restored, Israel of God. The important thing is whether or not you swear allegiance to the King of Kings and Lord of Lords. If you do, blessings and shalom upon you, fellow Israelite.