Why the King James Bible

There are many translations of the original Biblical texts these days. Many times people will complain that the King James Bible is "old english" and hard to understand. However, if one is to know the truth, you must know what the Bible truly says. Jesus said in John 17:17 "Sanctify them through thy truth: thy word is truth.". Only the King James Bible was translated under a King and has had such an intensive and dediciated effort to accurately translate the original Hebrew, Greek and Aramaic texts into English. Over the years, man has introduced numerous English translations, trying to make something better that didn't need improving.

In short, take any of the newer translations you have access to, such as the NIV and compare it to the King James Bible.
If so desired, you can compare online versions. Start with Acts 8:37
King James Bible
Other versions

God Promised to Preserve His Words See Psalms 12:6-7 "The words of the LORD are pure words: as silver tried in a furnace of earth, purified seven times. Thou shalt keep them, O LORD, thou shalt preserve them from this generation for ever."

Not only has man changed the original translation, but has intruduced new text and omitted others, something the Bible clearly condemns (see Revelation 22:18-19)
"18 For I testify unto every man that heareth the words of
the prophecy of this book, If any man shall add unto these
things, God shall add unto him the plagues that are written
in this book: 19 And if any man shall take away from the words of the
book of this prophecy, God shall take away his part out of
the book of life, and out of the holy city, and from the
things which are written in this book. "

There are many more thoughtful resources on this subject. Here is one to start >
How I Know That The King James Bible Is The Word Of God