In the Bible, it says clearly that no one should make a dare to edit or correct the Bible by any words. But many chapters and contents are extremely censored from the original Bible. How is this acceptable, and how do we know the truth and full story about the entire life?
(Finally, some of the replies and trolls I received made me more confused. But thanks a lot for the reference replies.)
That's not true. Bible translations differ wildly on the approach they take, but there exist many (at least for English) that are focused on offering a rendition as close to the original meaning as possible. Also, Biblical Hebrew and Aramaic as well as Koine Greek have been deeply studied over centuries and are well understood, so accurate translations are possible with the exception of a small percentage of rare vocabulary. Obviously, perfect translations aren't a thing, but that's a moot point and not exclusive to Bible translations.
Which scholars? Which translations? These blanket statements make no sense. Again, many translations have been made or reviewed/proofread by scholars of the Bible's languages, making your claim dubious at best.
It's no secret that settling on a canon was a process that took centuries both in Judaism (for the Tanakh) and in early Christianity (for its New Testament), and was never really finished in the latter case, considering the different canons in use in the major Christian churches even today.
That said, I think this process was a necessity. In early Christianity, there were hundreds if not thousands of Jesus-inspired texts floating around, so if the new church was to have any sort of guiding document(s), they had no choice but to pick and choose. Of course, if you think a text (like the Gospel of Mary you mention) is an important witness of the early church, or a more accurate reflection of early Christian thought than are the New Testament writings, you have every right to make that argument. But I don't think it's fair to hold it against early Christians that they "picked and chose what message they wanted", because that's kind of the whole point of founding a new religious movement.