A common, and admittedly impactful argument for KJVOnlyism is that some verses which appear in the KJV do not appear in other translations. An example can be seen in the header image. It is a chart which lists a number of verses, simply saying "YES" in the KJV's column, and big red bars saying "REMOVED", spanning across the rest of the translations.
This argument seems strong at first, because most people will look up the verses in the KJV, then compare it to the NIV and see that indeed, the verses do appear to be missing. But the argument gets weaker when, first of all, the circular reasoning is exposed. The majority of KJVOnly arguments assume, from the beginning, that the KJV is the standard. If, hypothetically, we were to take the opposite approach, we could as easily say the KJV has added the extra verses.
This, however, is not the approach I want to take, as while KJVOnlyists seem to take extreme pleasure bashing any translation other than the KJV, I have absolutely no problem with the KJV. It was the default translation I used in most newer Bible Brain articles when I started the site, it was the default translation I used in Path Treader Ministries posts, and there was even a time when I, myself, was KJVOnly. I still have the KJV I bought when I was convinced by that belief, and I actually have 2 KJVs right next to me as I write this. I have no problems with the KJV.
But then how do I reconcile this with the fact some verses have either been added to the KJV or removed from subsequent translations? Two words: Textual criticism. Textual criticism is the practice of studying copies of texts in order to ascertain what the original autographs genuinely said. Historically, people didn't have the advantage of the printing press or the photocopier. Books were written down by hand. This lead to copying mistakes, and means that there are many textual variants in the manuscripts we have available today.
When we compare these supposedly missing verses in greater depth than just "they're in the KJV, but not in these other translations", first of all, what we find is that not all translations directly omit them. A personal favorite of mine, the HCSB, instead opts to include the "missing" verses in brackets, with footnotes explaining the situation. In other translations, such as the much hated NIV, there are also footnotes present. Let's look at the top 3 examples:
Matthew 17:21 - "Some manuscripts include here words similar to Mark 9:29."
Matthew 18:11 - "Some manuscripts include here the words of Luke 19:10."
Matthew 23:14 - "Some manuscripts include here words similar to Mark 12:40 and Luke 20:47."
Notice a common theme here. "Some manuscripts include here words similar to these verses". And so you can turn to these verses and see, first of all, these verses haven't been removed. Mark 9:29, Luke 19:10, Mark 12:40, and Luke 20:47, are all present and correct in the NIV. The question arises, then, if the NIV is purposely trying to conceal these verses, why is it doing everything in its power to inform the reader about them? If you're translating a Bible and trying to remove verses, the absolute last thing you do is say in the footnotes "hey, we removed these verses, and they're super similar to these other verses we didn't bother to remove".
So what we see here aren't the marks of deception, but rather, evidence of diligence. Textual criticism is the process of trying to ascertain what the original text said. Thus, modern translators and textual critics shouldn't be referencing the KJV at all. It didn't show up until 1611. It's not the original, and Christians had the Bible a lot sooner than that. Thus, when you find older manuscripts than even the KJV translators used, especially if they are more numerous, you can get a better indication of what the original texts said, and even theorise on why later manuscripts differed.
This is where KJVOnlyists start talking about preservation, but the simple answer to that is the word of God is preserved. If God completely wiped the KJV from existence tonight, we would still have the preserved word of God tomorrow. Where? The same places it was in 1610, 1510, 1410, go back right to the time the last Apostle wrote the last word of the last Scripture, the word of God has been present throughout history. The translators of the KJV did their best with the evidence they had, the translators of modern translations do the best with the evidence they have. There are only three main differences: 1. We speak a very different version of English, 2. We now have piles of manuscript evidence more numerous, and older, than that used for the KJV, and 3. We now have a better understanding of the Koine Greek.
The missing verses argument, at least in my opinion, is the strongest argument KJVOnlyists have. Unfortunately, it is still only a surface level argument. Those who examine it in detail will find it wanting, as it is not only circular, but fails to take into account textual criticism. The verses aren't even missing; they are usually just repeats of similar Scriptures found elsewhere, and footnotes pretty much always explain the discrepancy. Furthermore, the allegedly missing verses aren't enough to alter theology. Just as with all discrepancies, these other translations will give you the same picture of theology as the KJV. If Satan intended to divide the Church by publishing altered and corrupted translations, he failed miserably. If, on the other hand, he intended to divide the Church by making us bicker over trivial issues like translation preferences, it would seem he succeeded spectacularly. The solution to corruption in the Church isn't to throw out the whole practice of textual criticism, which is effectively trying to find out what God originally said, but to instead listen to what He says in every reputable translation: "Now I beseech you, brethren, by the name of our Lord Jesus Christ, that ye all speak the same thing, and that there be no divisions among you; but that ye be perfectly joined together in the same mind and in the same judgment." (1 Corinthians 1:10). "But foolish and unlearned questions avoid, knowing that they do gender strifes. And the servant of the Lord must not strive; but be gentle unto all men, apt to teach, patient, In meekness instructing those that oppose themselves; if God peradventure will give them repentance to the acknowledging of the truth; And that they may recover themselves out of the snare of the devil, who are taken captive by him at his will." (2 Timothy 2:23-26).