Many Christians do not bother to check where their bible came from. During the time of Jesus, the known bible is what we know now as the Old Testament. How do we know how many books are in this bible ? You have to read my blog on Septuagint.
Jesus died in the year 33 AD then the New Testament was written in the second half of the first century about 20 years after the crucifixion. That means between 33 and 50 there was no New Testament. After the protestant reformation, Luther also removed 7 books of the Old testament. Why did I mention those two things ? That means in these instances the “Bible Alone” belief fails. Beside the fact that “Bible Alone” is not biblical.
Most of the Old Testament was written in Hebrew, some in Aramaic and some in Greek while the New Testament was written in Greek. That means all the English bibles we have are translations and depending who did the translation depends your understanding of the bible. That is why in the Catholic tradition we read the bible with the Church otherwise you will be misled. This is why there are many Christian denominations today with varying interpretation of the bible.
How do you read the bible ? Like I said above always read it with the Church. One of the first things one should look for is good footnotes at the bottom of the page that are indexed to other similar texts in the Bible. This helps the reader to understand the particular verse in context, rather than in isolation. The Bible is meant to be read in its entirety, and never to be taken out of context. That is what satan tried to do to Jesus in the desert in Matthew 4 – Taking individual verses out of context, trying to use them to mean something they really don’t.