Friends, I am a Bible Believing Christian, and I believe God has kept His Word in safe hands through the ages, so we will know that His Testimony is True.
Please just understand, that Some things were added by copyist's, most likely as marginals to explain certain things, but unfortunately crept into the KJV. Though they are there, and not in some modern translations, does not mean we should throw the Bible out. It is the Word of God.
I suggest you read a book by Lee Strobel, where he interviews Scholars on these subjects, the book is called : The case for the Real Jesus.
Due to these differences, some so called scholars are attacking the Inspiration of the Word, We need to understand that, though there are some "errors" in the KJV, that the crux of the message stays the same. That the Prophetic applications remain and that we do have a Word which we can really trust.
Just to look at a few other texts
Mark 15: 3. He answered nothing.
Textual evidence attests the omission (cf. p. 146) of these words here in Mark.
[Nichol, Francis D.: The Seventh-day Adventist Bible Commentary : The Holy Bible With Exegetical and Expository Comment. Washington, D.C. : Review and Herald Publishing Association, 1978 (Commentary Reference Series), S. Mk 15:3]
1 John 5:7
In heaven. Textual evidence attests (cf. p. 10) the omission of the passage “in heaven, the Father, the Word, and the Holy Ghost: and these three are one. And there are three that bear witness in earth.” The resultant reading of vs. 7, 8 is as follows: “For there are three that bear record, the Spirit, and the water, and the blood: and these three agree in one.” The passage as given in the KJV is in no Greek MS earlier than the 15th and 16th centuries. The disputed words found their way into the KJV by way of the Greek text of Erasmus (see Vol. V, p. 141). It is said that Erasmus offered to include the disputed words in his Greek Testament if he were shown even one Greek MS that contained them. A library in Dublin produced such a MS (known as 34), and Erasmus included the passage in his text. It is now believed that the later editions of the Vulgate acquired the passage by the mistake of a scribe who included an exegetical marginal comment in the Bible text that he was copying. The disputed words have been widely used in support of the doctrine of the Trinity, but, in view of such overwhelming evidence against their authenticity, their support is valueless and should not be used. In spite of their appearance in the Vulgate A Catholic Commentary on Holy Scripture freely admits regarding these words: “It is now generally held that this passage, called the Comma Johanneum, is a gloss that crept into the text of the Old Latin and Vulgate at an early date, but found its way into the Greek text only in the 15th and 16th centuries” (Thomas Nelson and Sons, 1951, p. 1186).
Nichol, Francis D.: The Seventh-day Adventist Bible Commentary : The Holy Bible With Exegetical and Expository Comment. Washington, D.C. : Review and Herald Publishing Association, 1978 (Commentary Reference Series), S. 1 Jn 5:8