Complex sentence: Under the reign of James I, there was a general Calvinist consensus in the Church of England, but Puritans believed worship practices needed to be supported implicitly or explicitly by the Bible, while their opponents gave greater authority to traditional customs.
Split into simpler sentences: Under the reign of James I, there was a general Calvinist consensus in the Church of England. Puritans could be distinguished by their insistence that worship practices be supported implicitly or explicitly by the Bible, while their opponents gave greater authority to traditional customs.