What do you mean by "treatment" ? Don't you rather mean "Testament" ? If you do, I think I may help you a little.
I don't think we know where the Old Testament comes from. When scientists tried to analyze the text ( this is called an "exegesis" ) at the end of the XIXth century / beginning of the XXth century, they found there were four "traditions", i.e. ways of writing, called "heloist", "yahvist", deuteronomist" and "priest". The Church said it was normal, since the Bible was written by men, not directly by God ( this is why there are problems with the exegesis of the Coran, which is supposed to be the words of God himself... ).
The New Testament is said to have been written by four disciples of Jesus, Mark, Johannes, Matthew and Paul. Three of them are originally in Greek, the last one in Aramaic. I never remember which one is this. I think it is Mark, but I am not sure at all. These are the "official" gospels, recognized by the Church. But actually, others were found, especially in the Egyptian desert. They are called the "apocryphal gospels", because their authenticity is doubtful : we don't know whether they tell the truth or are mere fictions. It is thought that there were more than four gospels written after Christ's death and that the Church rejected some of them, either because they were false or because they didn't correspond to the "official story".