During the forty days after his crucifixion, he appeared to the apostles from time to time and proved to them in many ways that he was actually alive. On these occasions he talked to them about the Kingdom of God.
In one of these meetings as he was eating a meal with them, he told them, "Do not leave Jerusalem until the Father sends you what he promised. Remember, I have told you about this before.
John baptized with water, but in just a few days you will be baptized with the Holy Spirit."
When the apostles were with Jesus, they kept asking him, "Lord, are you going to free Israel now and restore our kingdom?"
"The Father sets those dates," he replied, "and they are not for you to know.
But when the Holy Spirit has come upon you, you will receive power and will tell people about me everywhere -- in Jerusalem, throughout Judea, in Samaria, and to the ends of the earth."