NOTES for Act 7:1-59
Stephen reminds those gathered of the historical path traveled by the people led by God, but he focuses attention on those episodes when the people rebelled against His will, rejected or failed to understand the prophets whom the Lord sent. There could have been more examples, but those Stephen mentioned were enough to bring his listeners right up to the thought that belonging to the tradition alone does not automatically ensure following the faithful course and does not guarantee obedience to God's will.
One can memorize many things; one can understand ritual prescriptions well and even be fluent in the text of Scripture. But if the heart proves closed, it is very easy not to recognize the One whom one supposedly awaited and on whom, as it seemed, one had placed all hope.