Translations of the Bible are poor substitutes for the word of God given to us in the ancient languages—and the poorness of the substitute is greatly increased by the use of an inaccurate translation in archaic English! Moreover, no translation of the Bible is a really good one unless the user of it understands the guiding principles and practices that the translators followed—and that is why it is so very important to very carefully read and understand the information provided in the preface.
Do you mean translation is not the words of God? Translation is not about substitution. It is the equivalent rendering in other languages. What is really needed to understand God’s word is Prayer and study. The Preface of any Bible including the KJV is not given by inspiration. The text of the KJV is!