A year ago, I posted a comment on this thread that briefly described a process of reinterpretation that occurred in the first few decades of Christianity. It appears to be consistent with the evidence to suggest the movement spawned from a branch of Judaism that perceived through the OT texts that God had sent a Christ/Logos (etc.) and deliverance of the 'chosen' was immanent. Jews were believed to play a central role in the dispensation of world governance.
Pretty early on both premises fell out of favor.
It's my conclusion that the Gospel story was crafted as a didactic parable/tale that introduced and demystified spiritual concepts through dramatization for a later generation. The popularity of that story reshaped the movement in profound unanticipated ways.
The Gospel/s generally depict the disciples as thick headed, as they served as foils for outdated ideas or popular misconceptions. Acts follows that tradition further (and also attempts to domesticate Paul and groups that he inspired).
Therefore IMO, Acts 1:6-8 is a perfect example of a narrative crafted to polemicize against the outdated idea of an imminent Jewish-centric Messianism. The topic is shifted through the Jesus response toward a universal future objective, as decades had past and the church by then had broken from Judaism.
6 Then they gathered around him and asked him, “Lord, are you at this time going to restore the kingdom to Israel?”
7 He said to them: “It is not for you to know the times or dates the Father has set by his own authority. 8 But you will receive power when the Holy Spirit comes on you; and you will be my witnesses in Jerusalem, and in all Judea and Samaria, and to the ends of the earth.”
To imagine the closest confidants and friends of Jesus, having completely misunderstood 'his' message, is to not understand the narrative's purpose at all. The purpose is that the 'Spirit' was now teaching a more esoteric message, past Christians were mistaken in their expectations.
So, while, as was mentioned, the direction of movement was from a mystery/revelatory/experiential faith toward a formulaic text-based one; out of necessity the 'Kingdom' went from literal to metaphor in those same texts that cemented an orthodoxy.