Up to this point in the history of the church only Peter and John have been thrown in jail, beaten, and threatened to not speak, teach or heal in the name of Jesus.
At the end of chapter 6 we see Stephen, an early leader in the church, taken before the religious leaders. They falsely accuse him of speaking blasphemous words, against Moses, God and the holy place (the temple).
As Stephen stands before the counsel, he is going to use the old testament to bring them to the point to where they see that the same God that was in the Old Testament is the same God that is in the New Testament, and Jesus truly was God in the flesh.