A Gospel to Die For

The argument of Stephen's speech in Acts 7 is not easy to follow. Why is such a long, seemingly rambling retelling of Israel's history, included by Luke in his riveting account of the mission of the Spirit? Not many sermons lead to the death of the preacher. For this reason alone, Stephen's response to the accusations made before the Jewish council should be significant. What in Stephen's message created such rage resulting in the church's first martyr?
What is the connection between Stephen's stoning and a young religious zealot named Saul who gave his approval to the execution? Why does a slavish devotion to the external form of religion rather than coming to the reality of Christ always involve a 'resisting of the Holy Spirit'?