I believe KJV is the perfect translation of God's Word in English language.
No perfect translation exists.
The KJV is one of the best translations in the English language, no question about that. But all versions have errors, KJV included.
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Examples of major errors in the KJV:
1. The Pericope Adulterae
John 7:53 to 8:11 is the story of the adulterous woman, called the "Pericope Adulterae."
Among bible scholars, the consesus is that the Pericope Adulterae is a fake addition, called an "interpolation."
In the KJV, it is written in full, without explanation.
On this issue, the NIV (New International Version) is the better rendition. The NIV presents the verses in italics to clearly mark the interpolation, and includes this explanatory note:
[The earliest manuscripts and many other ancient witnesses do not have John 7:53—8:11. A few manuscripts include these verses, wholly or in part, after John 7:36, John 21:25, Luke 21:38 or Luke 24:53.] https://www.biblegateway.com/passage/?search=John+7&version=NIV That's why I never say, "who is without sin cast the first stone," as those familiar with my posts will notice. Anyone who uses those verses is likely a novice in bible studies.
2. The Johannine Comma 1 John 5:7-8 is called the "Johannine Comma" (in ancient Greek, a "comma" is a short clause).
The scholarly consesus is that the Johannine Comma is another fake addition or interpolation.
The KJV has it in full:
7 For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one. 8 And there are three that bear witness in earth, the Spirit, and the water, and the blood: and these three agree in one. (1 John 5:7-8, KJV) The NIV again has the better rendition on this issue, and renders it this way:
7 For there are three that testify: 8 the[a] Spirit, the water and the blood; and the three are in agreement. (1 John 5:7-8, NIV) Footnote (a) of the NIV states:
a.1 John 5:8 Late manuscripts of the Vulgate testify in heaven: the Father, the Word and the Holy Spirit, and these three are one. 8 And there are three that testify on earth: the (not found in any Greek manuscript before the fourteenth century) The likely motive of the interpolator was a strong belief in the Trinity doctrine, which I believe to be unbiblical.
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Other KJV errors:
http://www.ucg.org/bible-study-tools/booklets/how-to-understand-the-bible/are-there-mistakes-in-the-king-james-versionhttp://www.bible.ca/b-kjv-only.htm#errorshttp://watch.pair.com/TR-kjv-issues.html