This has been discussed in the forum at length in other threads.
Briefly - the Old Testament is a collection of writing, originally in Hebrew. The Jews of Judaea accepted one group of writings as their canon, and the Jews of Alexandria accepted those writings and a few more. The additional ones are collectively known as the Apocrypha. Christians accept the Apocryphal writings as useful but not essential. Roman Catholic editions of the Old Testament generally included the Apocrypha, Protestant editions generally did not.
The New Testament contains those writings (in Greek) which all Christians accept as being essential.
There are numerous translations, because the original writings were in Hebrew and Greek, which relatively few people can read. Just as with the Koran, any translation is an attempt to interpret the original, but a translation of the New Testament from Greek into English has no more or less validity than a translation of the Koran from Arabic into English. (As I do not speak Arabic, I have to rely on translations if I want to read the Koran, and I am not surprised when I find that the translations differ - if the exact meaning is important, then I read two or three different translations, and I still accept that I have not read the original words.)
Different English translations have been made over time, because no translation is perfect, and the English language changes, so some words in it become obsolete or change meaning. (We've discussed "charity" and "love" for instance in this thread.) Any translation ought to be as faithful a rendering of the original (unchanging) Hebrew or Greek as possible.
I prefer,for my use, the translation the we refer to as the King James' Version (or Authorised Version,) that is the translation made by a committee of scholars in the late sixteenth to early seventeenth centuries which was authorised for use in churches in England by King James I. Where I have been able to check, this version is very close to the original (I can only check the New Testament passages, because I don't know any Hebrew.) Unfortunately, the style of the King James' version is somewhat old-fashioned, which makes it difficult for some people to read.
There are some modern versions where the translators have not kept closely to the original meaning. You have expressed outrage that the meaning of the scriptures might be deliberately perverted in translation and I agree with you on that. So, if you wish to use passages from the Bible to argue about Christian doctrine you should use one that claims to be accurate, which comes back to my first post in this thread.
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You complain that non-Muslims will not even discuss the Koran. If this is true, on this forum, it is because any attempt to discuss the meaning of passages in the Koran is immediately met by Moslems with the statement that discussion is only acceptable within the framework of Moslem scholarship, which is neither within the experience or inclination of most non-Moslems. Any statement that implies that the Koran was not delivered directly from God by an angel, or that it is not necessary to believe every word of it, is regarded as an insult, which also makes discussion difficult.
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