In a lot of churches today you will hear Pastors say "if you go back to the Greek" when they preach.  This practice is forbidden by scripture.  (1 Cor. 14:26-28)  Most, if not all pastors that say this do not speak Greek.  But the King James translators actually spoke, read, and understood the language.  All of the King James translators spoke multiple languages.  The KJV translators were ordered by King James to translate the Old Testament only from the Hebrew, and the New Testament from the Greek.  However, modern Bible versions do not follow this practice, in fact they often favor the Septuagint, which is a Greek Old Testament.    The Old Testament was originally written in Hebrew.  But again, since new Bible translations do not actually believe their Bibles are the inerrant word of God, they favor the Septuagint in many places in the Old Testament.  

So who do you think actually knew what the Greek means, the KJV translators who all spoke multiple languages, or the Pastor who has a Greek lexicon but can only speak English?  And who do you think understood it better between the KJV translators who spent hours in prayer and went to great extremes to ensure they translated it right--one translator even going so far as to read every piece of Hebrew literature extant, or the modern scholars who sat in front of the television for hours, and grew up on soda pop and bubble gum?  You say, what difference does that make?  Most of King James translators spoke multiple languages from a young age, and likely grew up in strict homes where they learned to study and work hard at an early age.  The television did not exist and therefore was unable to corrupt their minds, and they grew up in a time when things weren't soft and easy.  John the Baptist and other great men of the Bible lived rugged lives.

There is so much on this subject.  The fathers of the modern Bible "versions", Westcott and Hort were both far from what you would call Bible believing Christians.  These are the men who produced their own Greek New Testament in 1881 which was the foundation for the "Revised Version".  The name alone ought to make a Christian stop and think....who is revising God's word?   Here are some statements from Westcott about his "faith":

People misunderstand those of us who are King James only. It's not that we think King James was some special person and that there was no Bible until 1611. The King James is just one Bible in a succession of Bibles that have contained the word of God throughout human history.  God has preserved his word for us, just like he did for every generation.  There are parts of the Bible translated into every language out there.  King James' role was commissioning a Bible translation for the common man.  The translators were all well learned men who spoke multiple languages and who believed the Bible was God's word.  They were not modern scholars who think God's word has passed away and needs to be dug up under a rock somewhere.  

And what motivation is there for making yet another new Bible version?

All modern Bibles except one are copyrighted.  Copyright laws state that the text has to be 4% different from other texts to be copyrighted.  When you are talking about a book as big as the Bibe, that's huge.  If we are to live by every word that proceedeth out of the mouth of God, we have to first have every word.  Not the thoughts, or the ideas, but the words.  

There is a lot of information out there about this subject.  I have endeavored to condense and present an extremely simplified version here.  Satan's very first attack on humanity was undermining God's word.  "Yea, hath God said?"  Therefore, we should be very vigilant when it comes to his word.  If you aren't convinced, please check out the audio/video section below.  There is an excellent documentary called "New World Bible Versions" and several sermons about the King James Bible and the errors contained in the other Bibles.