This author has read through, and made a study of, Tyndale's 1526 New Testament, Matthew's 1537 New Testament, and the 1557 Geneva New Testament. And he can testify that, while all three are extremely accurate, none of them are as accurate as the King James Version. They contain errors not found in the King James Version. These errors are not numerous, nor are they as serious (when taken as a whole) as those found within the modern versions; but the King James Version is a definite improvement over them all. It was the crowning achievement in the translation of the Bible into English.
Nor do any of the versions produced since the King James Version equal it in accuracy and faithfulness to the true text. As has already been pointed out, almost every one of the modern versions is based on a corrupt text; and so of course we can be sure that all of these are far inferior to the KJV, without even examining them further: the fact that they are based upon a corrupt text is sufficient. But we are considering, here, whether or not the KJV is the best translation of the true text available. In recent times a version has been published which is largely based on the true text, and which has gained increasing popularity in some circles. It is called the New King James Version, and it deserves a brief mention here because some are claiming that it fulfills the three criteria mentioned above: it is based on the true text, the Received Text; it is alleged to be an accurate translation of that text; it is, in fact, alleged to be the most accurate translation of that text, superior even to the King James Version.
When the New King James Version is examined, however, it is found to fall far short with regard to all these criteria. In the first place, although it claims to be based on the text underlying the 1611 KJV, in a number of places it most certainly does not follow that text, but departs from it; for example, in 1 Cor.10:6,7, Heb.10:17, Revelation 14:3, Revelation 5:13, and Rev.16:5.
In the second place, there are numerous changes in the English between this version and the KJV. It has been calculated that there are about 1500 changes in the English in just the first eleven chapters of Matthew, suggesting a total of about 30 000 to 35 000 in the entire New Testament, affecting perhaps on average one word in every five or six. In the third chapter of John, there are 222 changes. The NKJV drops all usage of the words thou, thee, thy, and thine. This modernisation of the English actually affects the accuracy of translation, because the Hebrew and Greek languages contain distinctions between the singular and plural personal pronouns–distinctions which are not made when the modern you and your are used. The accuracy is affected in such places as Lk.22:31,32, and Philemon vss.1-3, 20-22,23,25.
There are a number of places where the NKJV rendering affects true doctrine. Here are a few: Matt.20:20, Rom.4:25, 1 Cor.1:18, 1 Cor.8:11, 2 Cor.2:17, 2 Cor.5:14, 2 Cor.10:5, Phil.2:6, 1 Thess.5:22,23, Heb.2:16, Rev.19:8.
There are many footnotes in the NKJV, indicating manuscript readings which differ with the traditional text, but these merely serve to confuse the reader who is not informed about these issues, and to cast doubt upon the authenticity of the true text at these places.
The above facts, though brief, are sufficient to demonstrate that the so-called `New King James Version' is not a more accurate translation, but is far inferior to the King James Version. It should be rejected by all lovers of the Word of God in favour of the King James Version.