A few days ago I had a discussion on an Apologetics website with some well-intentioned but naive believers who were convinced that the omission in modern Bible translations of several verses originally printed in the KJV is indicative of a Satanic conspiracy to subvert God’s Word, involving a number of Bible publishing houses. I regularly come across this kind of uninformed belief. For those who may be interested in this old chestnut, what follows below is the response that I posted on the apologetics forum:

The Greek manuscripts available to the King James translators came from the Byzantine family of manuscripts (referred to as the Textus Recepticus), dating from the 5th century and later. The Byzantine text was the dominant Greek text from the 8th century until 1889. By the 1800’s, however, thousands more Greek manuscripts had been discovered, including many that were dated much earlier and were more reliable than the Byzantine text. These earlier manuscripts include the much more reliable Vaticanus. Although this had been discovered in 1475, it remained locked away in the Vatican vaults and the KJV translators were refused access to it. This was because of the Catholic church’s opposition, at that time, to translations of the Bible into anything other than their own Latin version. The Vaticanus was only released and made available to Bible translators in 1889.
Other, more reliable, Greek manuscripts which weren’t available to the KJV translators include the Alexandrinus (discovered in 1621, just 10 years after the KJV was published), and the Sinaiticus, the earliest, and most reliable, complete Greek New Testament in existence, discovered in a monastery in Sinai in 1875, and dated at 330 A.D. By 1889 these, and many other Greek manuscripts had begun to circulate. When compared to these, the Byzantine text, upon which the King James Version had been based, was vastly inferior – containing many transcription errors and interpolations.
The Byzantine text is no longer relied upon by modern translators. Because of its reliance upon flawed Greek texts, the KJV published many interpolations which we now know were not in the original text. For example, the KJV renders 1 Corinthians 6:20 as, “Therefore, glorify God in your body and in your spirit, which are God’s”. The words, “and in your spirit, which are God’s” are an interpolation, found in the Masoretic and other later texts, but not in any earlier texts. In other words, these words are not in the original text of 1 Corinthians 6:20. This interpolation was introduced by monastic copyists in the 8th century, at a time when Greek philosophy, which emphasised the spirit and de-emphasised the body, had influenced Christian theology. Modern translations do not publish this interpolation in their text.
This is just one of hundreds of problematic interpolations published in the KJV, as a result of its reliance on later, less reliable manuscripts. These flawed Greek manuscripts were combined into a published Greek text called the Textus Receptus, and it was this published text that was used for the KJV translation. The accepted Greek text that is used by today’s Bible translators differs from the flawed Textus Receptus in over 2,000 textual locations!
One outcome of the KJV’s use of the Textus Receptus is that there are a number of verses that were published in the KJV (and, therefore, given verse numbers), which are not published in modern Bibles, because they are now known to be interpolations. These verses include Matthew 17:21, Matthew 18:11, Matthew 23:14, Mark 7:16, Mark 9:44, Mark 9:46, Mark 11:26, Mark 15:28, Luke 17:36, Luke 23:17, John 5:4, Acts 8:37, Acts 15:34, Acts 24:7, Acts 28:29 and Romans 16:24. None of these verses appear in modern translations, but in order to retain a consistent verse numbering system, modern Bibles simply skip that verse number. For example, in most modern Bibles, Matthew 17:20 is immediately followed by Matthew 17:22. Verse 21 is either footnoted or does not appear at all.
Apart from textual inaccuracy, the KJV also suffers from obtuse language and cumbersome sentence structure, often making it difficult for modern readers to understand. John 18:34 is a case in point. The KJV renders it, “Jesus answered him, “Sayest thou this thing of thyself, or did others tell it thee of me?”.” The NIV and TNIV offer a more readily understandable version; “Is that your own idea?” Jesus asked. “Or did others talk to you about me?”
Thank you for thar explanation Kev