To say that the Bible is authoratative is also to say that the Koran and every other Holy Text ever written is authoratative. Who are we as Christians to say that our God's version is the ONLY version? And if they are all authoratative and they all conflict with each other in many ways (not unlike the Bible conflicting with itself in many instances), then which one is "right"? Certainly, it is impossible and ridiculous to suggest that any of the holy texts are completely "right". Logic simply does not allow this.