"On one occasion, while he was eating with them, he gave them this command; 'Do not leave Jerusalem, but wait for the gift my Father promised, which you have heard me speak about. For John baptised with water, but in a few days you will be baptised with the Holy Spirit.'
So when they met together, they asked him, 'Lord, are you at this time going to restore the kingdom to Israel?'
He said to them: 'It is not for you to know the times or dates the Father has set by his own authority. 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.'"
I love the way Luke writes, it's the little pictures of ordinary everyday life that he gives us. "On one occasion, while he was eating with them..." Why does Luke add that? Why not just write "On one occasion he gave them this command..."? Because Luke records the ordinary parts of life that remind us that amazingly Jesus is God made man. This is after his resurrection too, after he had his resurrection body, yet he still takes time out to eat with them. The resurrected glorified Jesus spends time after his resurrection eating with his disciples, a sign of welcome, care, friendship. The resurrected Jesus isn't too busy for friendship he takes time out to eat with his disciples. It's a great picture of what it means to follow Jesus.
While eating with them he tells them not to leave Jerusalem. He tells them to wait. To wait for the Holy Spirit promised. It's a phrase that takes us back to Luke 3v16 where John the Baptist loudly proclaims "...one who is more powerful that I will come, the thongs of whose sandals I am not worthy to untie. He will baptise you with the Holy Spirit and with fire." Jesus is that powerful one. But it also takes us further back to Joel 2 and the promise that Peter speaks of fulfilled at Pentecost. Jesus doesn't leave his people alone, he doesn't send them to do mission in their own strength, Jesus sends the Holy Spirit.
Now the excited disciples expect the kingdom to come straight away. But Jesus teaches them about the nature of the kingdom. It is much bigger than they expect. God's kingdom is not about one nation but the reconciliation of all nations to God, it is God's promise to Abraham of blessing all nations fulfilled. And he teaches them about the timing of the kingdom. The kingdom is both now but also not yet. It has come because the King has come, and they are the King's people, they are the kingdom, but it will only be fully realised when he returns. I can't help but wonder if the disciples shoulders slumped in disappointment at Jesus response to their question like a child on Christmas morning told that they have to wait until after church to open their presents (seriously? What sort of parent would do that to their children!).
But Jesus shows them the part they play in bringing the kingdom. They are to wait for the kingdom to come, expectant and active. Full of the Spirit they are to take the good news of Jesus to the world. That task continues today, in one sense Acts is unfinished, we live in its final chapter. Equipped and filled by the Holy Spirit called to witness to Jesus to the ends of the earth.
Don't shrink the kingdom. God's vision of his kingdom is vast, it is all nations encompassing, it is growing, it is eternal, it is glorious. And amazingly he calls and equips us to play our part in bringing the kingdom, in growing it, in making Jesus known, and spreading his glory.