Why do the Bibles of Protestants, Catholics, and Orthodox Christians differ?

Why Do the Bibles of Protestants, Catholics, and Orthodox Christians Differ From One Another?

There are three primary books in the Bible.

The set of religious texts that make up the Bible is known as the canon.
The Protestant Bible contains 66 books: 39 from the Old Testament (OT) and 27 from the New Testament (NT). The Catholic Bible contains 73 books: 46 from the OT and 27 from the NT.

The New Testament canons of the Protestant, Catholic, and Orthodox churches are all the same.
The Old Testament canons are distinct; explain how and why.
Since the OT books were written so long ago, there is little historical evidence to reconstruct how they were originally written.
In any case, let’s back up and start from the beginning.

An Overview of the Old Testament (also known as the Hebrew Bible or the Tanakh)

By its very nature, the Old Testament begins with the presumption that God exists, since it is God who is shown to be responsible for the beginning of time and all of creation.
The Jewish people believe that Moses wrote the first five volumes of the Old Testament, which are together known as the Pentateuch.
Moses, who probably lived in the 15th century B.C., writes about and records historical events that occurred long before his time (the creation, Noah, Abraham, etc). (Egyptian bondage, the Exodus, wilderness wandering, etc.).

Now is the time to act.

Throughout Israel’s lengthy history, there have been numerous prophets whose words were accepted as authoritative because of their status as God’s representatives.
Scholars of Judaism in the years before Jesus’ birth agreed that the canonical OT scrolls, written by a line of prophets, span the years between around 1500 B.C. and 400 B.C. (and then Protestant scholars in the centuries after his birth).
Books were eventually shelved together as the canon grew and scrolls expanded.

Tradition holds that Ezra was primarily responsible for assembling the holy texts into a standard canon, albeit this cannot be verified.
To put it simply, just as the Holy Spirit inspired people to produce the books, so too did the Spirit inspire people to keep and value the books.
There is no general agreement among scholars as to when the Hebrew Bible canon was set, however some have speculated that it was approximately 100 BC.

Books that were later discarded or forgotten (also known as the Deuterocanonical Books)

Books published by Jewish authors between the latter two centuries B.C. and the first century A.D., but not included in the official Hebrew canon due to their esoteric content, are referred to as “apocryphal.”
For the benefit of the numerous Jews who did not know Hebrew, the Hebrew Bible and the Apocrypha (sometimes called deuterocanonical or “secondary canon”) were translated into Greek in the third century BC.
The Greek word for “seventy,” from which the name of this translation derives, is “Septuagint,” in reference to the common belief that 72 different rabbis contributed to its creation.
It is commonly shortened to “LXX” (70 in Roman numerals).

During the time that the New Testament was being formulated, the LXX was widely used by Jews and Jewish Christians, therefore it was naturally adopted by Christians as the Old Testament of the Christian Bible.
The Jewish rabbis, however, rewrote their Scripture and established a canon of Judaism around the year 100 AD, leaving out several books from the Greek Septuagint in the process.
In this case, the Hebrew editions of Jewish Scripture did not include a collection of fifteen late Jewish writings produced between 170 BC and AD 70.
Instead of adopting the revised Hebrew Bible, Early Christians stuck with the LXX translation of the Old Testament.

When the church split into Catholic and Protestant denominations in the 1500s, Protestant leaders decided to separate the OT books from the rest of the Bible and organize them according to the official canon of Judaism rather than the LXX. This arrangement remained in place until the middle of the 1800s.
Bible publishers gradually stopped include the Apocrypha in their Protestant editions as they came to view it as less essential.

Both the Roman Catholic Church and the Orthodox Church, which reveres an even wider range of texts, continued to use the LXX as the foundation for their Old Testaments.
As a result, these Bibles contain more books from the Hebrew Scriptures than typical Protestant Bibles.
Aside from the episodes of Susanna and Bel and the Dragon found in Daniel, the Catholic Old Testament also includes Baruch, the Letter of Jeremiah, Tobit, Judith, The Wisdom of Solomon, Sirach (Ecclesiasticus), additions to Esther, and the Prayer of Azariah.
Some of these books are found in an appendix to the Old Testament, but the Orthodox Bible also includes 1 and 2 Esdras, the Prayer of Manasseh, Psalm 151, and 3 and 4 Maccabees.

There are some discrepancies in the Bibles, but every major Old Testament book and every New Testament book are included in every Bible.
Finally, think on what is said in Hebrews 4:12 and 2 Timothy 3:16-17.