The King James Version is the only pure or authorized English Bible

The KJV was never a from-scratch translation: it was an update. The roughly fifty translators who worked on it between 1604 and 1611 started from a printed 1602 Bishops' Bible, cross-checked the Geneva Bible, and revised against the Greek and Hebrew rather than starting over. In their own words, printed in the front matter of the 1611 edition, their goal was "not to make out of a bad Bible a good Bible, but to take a good Bible and make it better." Roughly 70 percent of the King James New Testament is actually William Tyndale's wording from decades earlier: the translators deferred constantly to his skill rather than replacing it.

The kill shot against KJV-onlyism is that the KJV's own preface argues against it. In their address "The Translators to the Reader," the 1611 team wrote that as language changes, the wording of Scripture should change too, so that it stays understandable: change for clarity, not a claim that their wording was uniquely inspired. They used the analogy that even a poor translation of a king's speech is still the king's speech: a translation doesn't need to be perfect, or singular, to faithfully carry the original meaning. A position that treats one 1611 English translation as the only legitimate Bible is a position the men who made that translation explicitly did not hold.