Until you are clothed with power ...
Then he said to them, “These are my words that I spoke to you while I was still with you, that everything written about me in the Law of Moses and the Prophets and the Psalms must be fulfilled.” Then he opened their minds to understand the Scriptures, and said to them, “Thus it is written, that the Christ should suffer and on the third day rise from the dead, and that repentance and forgiveness of sins should be proclaimed in his name to all nations, beginning from Jerusalem. You are witnesses of these things. And behold, I am sending the promise of my Father upon you. But stay in the city until you are clothed with power from on high.”
Earlier in this passage Jesus told these same listeners that they were "slow of heart to believe all that the prophets have spoken". The problem that his disciples had was not one of knowledge but one of faith. When the word of Christ's resurrection came to them they had already heard Jesus speak of it before he died on the cross. These could not claim ignorance. As they stood before Jesus faith arose in their hearts and he was able to open their minds to the truth.
Even though their minds were being transformed they were still not ready for the road ahead of them. These who witnessed the miraculous works of Christ and saw him first hand after he was raised from the dead still needed something they did not have. They, like each of us, needed the Holy Spirit ... they needed to be clothed with divine power ... they desperately needed to experience the promise of the Father. So it is with us - we need the power of God.
Come Holy Spirit and fill us and baptize us afresh today. We so need to be clothed with your power.