So what are the differences? Why are the translations different? How to know which one to follow?
Translations are different because that’s the nature of translating from one language to another. Do you have any familiarity with another language besides English? If so, you’ll know that just about any paragraph or even phrase can be translated in a number of equally valid, but different ways.
The most important thing to learn about the Catholic view of the Holy Scripture is that the teachings of Christ were communicated to the Catholic Church first – before they were written in a New Testament Bible.
So, the Gospels and Epistles are part of the Sacred Tradition (what was handed down from Christ) of the Church. The Protestant view is Sola Scriptura – where the empahsis is placed on the written word. This causes severe problems when one Protestant group rejects the translation of another – because they focus on the written word without any Sacred Tradition to support it. This gets so extreme that there are even people who believe in a King James Only view of Scripture – as if that is the only version that is valid.
Joseph Smith really absorbed the Protestant Evangelical view of the Scriptures. His belief about the Book of Mormon was that it was required to purify the Scriptures. But that is an outcome of the Sola Scriptura view. He did not know that the Bible was given to him through the Catholic Church – and thus was possessed in its fullness by Catholicism since the time of Christ.
Just as the early church did not have a codified, written text to work from in preaching and teaching, we accept now that the true doctrines of Christ can be transmitted (in part) through any authorized translation of Scripture.
There are several authorized Catholic translations for one reason because the English language has changed quite a lot over the centuries. Words and idioms change and thus new translations are needed.
Additionally, creating a good translation requires a certain amount of literary artistry and different talents can replicate the poetry of the sacred text in different ways.
But over all, a simple answer is that any authorized Catholic version of the Bible is good. I prefer the Confraternity Douay-Rheims version (the Catholic bible used in the 1950s) and also the Msgr. Ronald Knox version.
The Church approves different versions because the Orthodoxy of Catholic teaching is preserved by the Magisterium of the Church and it can be reflected in different versions.