They include several Jewish writings from the centuries just before Jesus — such as Tobit, Judith, 1 and 2 Maccabees, Wisdom, and Sirach — that are not in the Hebrew Bible.

Catholics call these books deuterocanonical, meaning "second canon", and Protestants usually call them the Apocrypha. The Jewish Bible never included them, and at the Reformation Protestants followed the Jewish list for the Old Testament. The Catholic Church formally affirmed them at the Council of Trent in 1546, and the Orthodox churches accept a slightly longer list again. All three agree on the twenty-seven books of the New Testament.

The Old Testament in Hebrew, with a few sections in Aramaic; the New Testament in Greek.

The Aramaic passages are parts of Daniel and Ezra and one verse of Jeremiah, reflecting the years when Aramaic was the common language of the Near East. The New Testament Greek is Koine, the everyday Greek of the Roman world, not the literary Greek of the philosophers. Jesus himself most likely spoke Aramaic day to day, and a few of his Aramaic words are kept in the Gospels.

Daniel 2:4

Over a thousand years or more, by dozens of writers including kings, priests, prophets, shepherds, a tax collector, a doctor, and fishermen.

The oldest parts of the Old Testament go back well before 1000 BC and the last books of the New Testament were written near the end of the first century AD. That range explains why the books sound so different from one another. It also explains why the Bible can refer back to itself: later writers had the earlier books and quote them constantly.

The Law (Genesis to Deuteronomy), History (Joshua to Esther), Poetry and Wisdom (Job to Song of Songs), the Major Prophets (Isaiah to Daniel), and the Minor Prophets (Hosea to Malachi).

The books are grouped by kind, not by date. That catches many readers out: the prophets are printed after Esther, but most of them lived during the events of 1 and 2 Kings. Reading Isaiah is easier once you know it belongs in the middle of Kings, not after it.

In three parts — the Torah (Law), the Nevi'im (Prophets), and the Ketuvim (Writings) — which gives it the name Tanakh.

The content is the same as the Protestant Old Testament, but the order differs and the count is twenty-four, because books like Samuel, Kings, and the twelve minor prophets are each counted as one. The Hebrew Bible ends with Chronicles rather than Malachi. When Jesus speaks of "the Law and the Prophets", or "the Law of Moses, the Prophets, and the Psalms", he is using this Jewish arrangement.

Luke 24:44

Four Gospels, then Acts, then thirteen letters of Paul, then eight other letters (Hebrews to Jude), then Revelation.

The Gospels tell the life of Jesus, Acts tells the spread of the church after him, the letters were written to churches and individuals, and Revelation is a vision of how everything ends. Like the Old Testament, it is arranged by type. Paul's letters, for example, were written before any of the Gospels, even though they come after them.

They were added long after the books were written: chapters in the early 1200s, commonly credited to Stephen Langton, and New Testament verses by the printer Robert Estienne in 1551.

The Old Testament verse divisions come from earlier Jewish scribal tradition. None of the numbering is part of the original text, and it sometimes cuts a sentence or an argument in half. It is a reference system, like page numbers, and a verse read on its own may not be a complete thought.

Covenant. The two testaments are the writings of the old covenant God made with Israel and of the new covenant made through Jesus.

The phrase "new covenant" comes from Jeremiah, who promised that God would one day make a new covenant and write his law on people's hearts. At the Last Supper Jesus called the cup "the new covenant in my blood". Calling the halves of the Bible "old" and "new" is not a judgement that one is out of date; it names the two agreements the whole story turns on.

Jeremiah 31:31

The Jews lived under Persian, then Greek, then briefly independent, then Roman rule, and much of the world Jesus was born into took shape.

Alexander the Great spread the Greek language across the region, which is why the New Testament is in Greek. Synagogues became central to Jewish life, and groups such as the Pharisees and Sadducees formed. None of this is narrated in the Protestant Old Testament, so a reader who goes straight from Malachi to Matthew meets a changed world without explanation.

The ancient Greek translation of the Old Testament, made in Egypt from the third century BC onward.

Its name means "seventy", after a legend that seventy-two scholars translated it, and it is often written LXX. It was the Bible of Greek-speaking Jews and of most of the earliest Christians, and New Testament writers often quote it. That is why an Old Testament quotation in the New Testament sometimes reads a little differently from the verse in your Old Testament, which is translated from the Hebrew.

Ancient manuscripts found in caves near the Dead Sea from 1947 onward, including copies of every book of the Hebrew Bible except Esther.

Before the discovery, the oldest complete Hebrew manuscripts of the Old Testament dated from around AD 1000. The scrolls were about a thousand years older. When scholars compared them, including a complete scroll of Isaiah, they found the text had been copied with remarkable care over that millennium, with mostly small differences of spelling and wording.

Some aim to follow the original words and word order closely, others aim to give the meaning in natural modern English, and most sit somewhere in between.

No translation can do both perfectly, because Hebrew and Greek do not map word for word onto English. A close translation keeps more of the original's shape but can read stiffly; a meaning-based one reads easily but makes more decisions for the reader. Comparing two or three translations of a hard verse is one of the simplest ways to see where the real difficulties are.