You see, the Greek and Hebrew were tampered with by an apostate by the name of Origen in the late 2nd Century AD. I have no problem with referring to Hebrew and Greek dictionaries and helps, but one must be careful which Hebrew and Greek they use. A good rule to go by is that they must conform to the KJV, because it is clearly the Word of God. Many times what is passed off as "the originals" is Origen's corruption of the original. I have both Origen's corrupted Greek and the Received Greek Text (Textus Receptus). The KJV (as well as some other languages) is based upon the Textus Receptus, whereas the modern English versions (as well as most other language version) are based on Origen's corruption.
The Word of God is the believers only offensive weapon. Satan is very much interested is destroying it, but he will never succeed. I must disagree with those who say that "Bibles are all just translations from the original languages." The KJV is the preserved Word of God. It is the inspired Word of God. It contains derivative inspiration from the originals and ancient translations (i.e. Syriac & Italic).
Concerning which KJV: There is only one, the 1611. The 1769 issue merely updated the spelling, but it is the same translation as the 1611. The New King James Version is based on Origen's manuscripts, and cannot be considered to be the KJV.
Ultimately it all boils down to faith. Is our Almighty God able to preserve His Word or not? I, for one, believe God. A man's name is only as good as his Word. So it is with God! We no longer have the original manuscripts, but God did promise to preserve His Word:
Psalm 138:2: "I will worship toward thy holy temple, and praise thy name for thy lovingkindness and for thy truth: for thou hast magnified thy Word above all thy name."
Psalm 12:6-7: "The words of the LORD are pure words: as silver tried in a furnace of earth, purified seven times. Thou shalt keep them, O LORD, thou shalt preserve them from this generation for ever."
Psalm 18:30: "As for God, his way is perfect: the Word of the LORD is tried: he is a buckler to all those that trust in him."