You will, you shall. I love it! They will be witnesses, according to Strong's, "in a legal sense, an historical sense, and in an ethical sense" as martyrs. This is not a suggestion, this is Christ, God telling them what is going to happen. "You will receive." According to Strong's, this is not just an I'm going to send you something in the mail type of verb, this is an active verb on the disciple's part, they are "a. to take with the hand, lay hold of, [this power] in order to use it. 1. to take up a thing to be carried, 2. to take upon one's self...c. to take what is one's own, to take to one's self. to make one's own." (#2983) They are going to be given God's power to make their own, in order that they might be his witnesses and glorify Him. They are given the power to be as Christ was and is. Strong's describes the ethical sense of being a witness as one who follows in the footsteps of Christ, those who die as he did for their faith, their knowledge, their truth.
Acts 1:14 "These all with one mind were continually devoting themselves to prayer, along with the women." They were all talking to God. That along is "with" and comes from the word for union.
One of the things I've been thinking about as I've been reading Acts, is the idea that they were witnesses. They testified about the gospel in a very culturally relevant way. First, with the Holy Spirit they spoke in different languages, languages that were recognized by people in the crowd. The Holy Spirit allowed them to speak in this way directly to certain people who were present. Christ is personal. Christ, the power of God, was revealed to them in a language they could hardly misunderstand. It was an amazingly cool, powerful experience. It showed off the strength of the power the Holy Spirit could give. These people were on the whole ordinary people, fishermen, and instantaneously they were given the knowledge and the words to coherently speak another language and speak truth into the lives of specific members of that crowd. Peter's response to those who mocked God's power as drunkenness, was to testify to all he had seen. He shared the gospel in a way that those in Jerusalem, Jews and others familiar with Jewish custom, would understand it. He quoted the prophets and reminded the crowd of what even they had witnessed in Jerusalem recently. They too were witnesses to a degree.
