The KJV is an excellent translation. However, one needs to consult other translations as well as the original texts to get a complete picture. No translation is perfect.
This is true, but only partially, as the word "
Easter" in Acts 12:4 is actually the word for Passover in the manuscripts. Jesus is our Passover sacrificed for us, Apostle Paul said. All English Bible translations have those kind of additions in them. And that's only half of the point.
Some English translations are setup hoaxes. When they claim to be just a revision of the original, they actually use additional Greek manuscripts which the original translators did not use. Erasmus translated the Greek
Textus Receptus (Received Text) from Byzantine Majority texts.
"When Erasmus classified the texts into two classes, one representing the Complutenian edition and the other the Vaticanus, he specified the positive grounds upon receiving the former and rejecting the latter. The former was in the possession of the Greek Church, the latter in that of the Latin; judging from the internal evidence he had as good reason to conclude the Eastern church had not corrupted their received text as he had grounds to suspect the Rhodians from whom the Western church derived their manuscripts, had accommodated them to the Latin Vulgate. One short insinuation which he has thrown out, sufficiently provides that his objections to these manuscripts lay more deep; and they do immortal credit to his sagacity. In the age in which the Vulgate was formed, the church, he was aware, was infested with Origenists and Arians; an affinity between any manuscript and that version, consequently conveyed some suspicion that its text was corrupted."
(An Inquiry into the Integrity of the Greek Vulgate or Received Text of the New Testament, 1815, p 413ff)
Erasmus who did the Greek
Textus Receptus translation mostly from Byzantine Majority texts, was aware of the heresies by some within the Alexandrian, Egypt school of Christians. Erasmus thus rejected the Alexandrian manuscripts as "corrupt", of which Codex Vaticanus is an Alexandrian text.
The
New King James Version Bible (NKJV) adds readings from the corrupt Alexandrian texts (
Vaticanus and
Sinaiticus) which the 1611 KJV translators did not use, nor did Erasmus even have
Sinaiticus which was only discovered in the 1850's.