There are bound to be errors in copying that make it impossible to know what the original meaning was
The Bible as we know it today contains 31,173 verses and even if scribes (the people who copied it) were extremely careful, it’s inevitable they would make simple copying errors. People say we can place no reliance on the infallibility of the Bible and many go even further, dismissing it as inaccurate and unreliable.
Jesus said ‘not the smallest letter, not the least stroke of a pen, will by any means disappear from the Law until everything is accomplished.’ (Matt 5:18) The ‘jot’ and the ‘tittle’ (as they are referred to in older versions of the Bible) were small symbols in the Hebrew alphabet which could alter the meaning of a word considerably (think of the English p and q or b and d, for example.) Clearly, a scribe had a difficult job when copying words when such tiny marks could alter the meaning of a word radically. Nonetheless, the most common mistakes (haplography, when a letter, word or phrase is missed out; dittography, when a letter, word or phrase is repeated and metathesis, when something is inverted by mistake) were generally quite easy to spot by those checking work (as indeed any proof-reader nowadays would say.) Because of the great reverence the Jewish scribes held toward the Scriptures, they exercised extreme care in making new copies of the Hebrew Bible. The entire scribal process was specified in meticulous detail to minimise the possibility of even the slightest error. The number of letters, words, and lines were counted, and the middle letters of the Pentateuch and the Old Testament were determined. If a single mistake was discovered, the entire manuscript would be destroyed.
As a result of this extreme care, the quality of the manuscripts of the Hebrew Bible surpasses all other ancient manuscripts. The 1947 discovery of the Dead Sea Scrolls provided a significant check on this, because these Hebrew scrolls antedate the earliest Masoretic Old Testament manuscripts by about 1,000 years. But in spite of this time span, the number of variant readings between the Dead Sea Scrolls and the Masoretic Text is quite small, and most of these are variations in spelling and style (like the difference between the American spelling of color and the English spelling colour.)
The fact that we have more than one manuscript of the whole Bible and lots of manuscripts which have parts of the Bible means that we can compare the manuscripts and if there are copying errors, we have enough manuscripts to work out what the correct version is likely to have been. The Old and New Testaments enjoy far greater manuscript attestation in terms of quantity, quality, and time span than any other ancient documents and since the Scriptures continually refer to historical events which are verifiable, their accuracy can be checked by external evidence as well.