The Jewish Bible, known to Christians as the Old Testament (not including the Apocrypha), is primarily written in Hebrew. A few passages are in a related Semitic language, Aramaic.
The apocryphal books placed by some Christians in the Old Testament are often held to have been written in Hebrew or Aramaic, but many now exist only in translation, the originals having been lost.
The New Testament is written in Greek, with the occasional bit of Aramaic.
yet there are many words that have been translated wrong or read wrong as to imply other meanings. along with mistranslations are forgeries and stories and books that were predated to seem older than they are ( the book of Daniel being the biggest one)
Most versions of the Bible are sponsored by one or more Christian denominations. Thus, translators tend to have similar belief systems. Some denominations have long standing prejudices against other religions, sexual minorities, etc. This sometimes affects the accuracy of their translation.
Translators are under economic constraints: if they translate some verses as they actually appear in the original Hebrew and Greek, then long held prejudices would be threatened and many potential readers might reject the translation. Some pastors have favorite passages that appear to condemn Wiccans, other Neo-pagans and homosexuals. If a translation appeared in which those verses no longer condemned Witches or homosexuals, it is unlikely that those clergy would buy it or recommend it to their flock.
examples -
Matthew 6:13: The Lord's Prayer traditionally ends: "For thine is the kingdom, and the power, and the glory, for ever. Amen." This seems to have been absent from the original writings
Luke 3:22: This passage describes Jesus' baptism by John the Baptist. According to Justin Martyr, the original version of this verse has God speaking the words: "You are my son, today have I begotten thee." Justin Martyr, Clement of Alexandria, Augustine, and other ancient Christian authorities also quoted it this way. 1 The implication is that Jesus was first recognized by God as his son at the time of baptism. But a forger* altered the words to read: "You are my son, whom I love." The altered passage conformed more to the evolving Christian belief that Jesus was the son of God at his birth, (as described in Luke and Matthew) or before the beginning of creation (as in John), and not at his baptism.
1 Corinthians 14:34-35: This is a curious passage. It appears to prohibit all talking by women during services. But it contradicts verse 11:5, in which St. Paul states that women can actively pray and prophesy during services. It is obvious to some theologians that verses 14:33b to 36 are a later addition, added by an unknown counterfeiter* with little talent at forgery.* Bible scholar, Hans Conzelmann, comments on these three and a half verses: "Moreover, there are peculiarities of linguistic usage, and of thought. [within them]." 2 If they are removed, then Verse 33a merges well with Verse 37 in a seamless transition. Since they were a later forgery*, they do not fulfill the basic requirement to be considered inerrant: they were not in the original manuscript written by Paul. This is a very important passage, because much many denominations stand against female ordination is based on these verses.
Revelation 1:11: The phrase "Saying, I am Alpha and Omega, the first and the last: and," (KJV) which is found in the King James Version was not in the original Greek texts. It is also found in the New King James Version (NKJV) and in the 21st Century King James Version (KJ21) The latter are basically re-writes of the original KJV. Modern English, is used, but the translators seem to have made little or no effort to correct errors. The Alpha Omega phrase "is not found in virtually any ancient texts, nor is it mentioned, even as a footnote, in any modern translation or in Bruce Metzger's definitive 'A Textual Commentary' on the Greek New Testament, Second Edition (New York: United Bible Societies, 1994..."
http://www.religioustolerance.org/chr_bibl.htmTexts in the Textus Receptus and KJV that were absent in the original Hebrew and Greek texts
http://www.bibletexts.com/kjvtexts.htm