Having a huge amount of trouble understanding Acts 7:15...Help?!?

Put it in context. Stephen (a believer in YAHUSHUA) is being accused of being untrue to the 'Jewish' religion. ('Jewish' means 'worshiper of YHVH'- and they, the Jews, had consistently been unfaithful to YHVH.) Stephen is reviewing their history to point out to them that it is they, not he, who is violating the covenants that YHVH has made with men over the years.