The Bible is made up of 66 books, but they are NOT arranged in the order that the events happened. This is one reason you are sometimes confused. But I'm about to clear it up for you. Ready?
A long time ago, certain people decided to arrange the Bible by grouping similar books together as follows:
Genesis, Exodus, Leviticus, Numbers and Deuteronomy
Joshua, Judges, Ruth, I and II Samuel, I and II Kings, I and II Chronicles, Ezra, Nehemiah and Esther
Job, Psalms, Proverbs, Ecclesiastes, Song of Solomon and Lamentations
Isaiah, Jeremiah, Ezekiel, Daniel, Hosea, Joel, Amos, Obadiah, Jonah, Micah, Nahum, Habakkuk, Zephaniah, Haggai, Zechariah and Malachi
Matthew, Mark, Luke and John
Romans, I and II Corinthians, Galatians, Ephesians, Philippians, Colossians, I and II Thessalonians, I and II Timothy, Titus and Philemon
Hebrews, James, I and II Peter, I and II and III John and Jude
Why does the Bible repeat itself so much?
If you wrote down the history of the United States from 1900 to 1960 and I recorded the history of New England from 1875 to 1975, then some of the major events would be found in both your book and in my book. Even then, the events would be recorded a bit differently. Also, you would have written down some events that I did not, and that's perfectly okay.
Well, this happened with the books of the Bible too.
If you found a letter written by your grandfather in 1943 during World War II, you could open up a history book and read more about what it must have been like for him living in that era.
Well, you can do that with the Bible too.
The Old Testament prophets had to be alive during some era of history. Most of the prophets begin their writings by recording who the kings were so you can know when they lived and prophesied. This would be like me beginning my writing with "during the US presidencies of Reagen, Bush, Sr., Clinton and Bush and the Iraqi presidency of Hussein..." If you weren't familiar with these presidents, then you'd have to search through the history books to find them.
For example, Isaiah 1:1 tells us that Isaiah the prophet lived and prophesied during the reigns of four successive kings in Judah: Uzziah, Jotham, Ahaz and Hezekiah. If you aren't familar with these kings, then you must search through the Old Testatment history books until you find them. When you do, you discover the record of these kings begin around II Kings 14:21 and II Chron 26:1.
This same principle applies to the New Testament also. As you read the history of the early church (Acts) you see a man named Paul traveling to different towns to preach the gospel. Later, after traveling to another location, he would send them back a letter to encourage them and strengthen their beliefs. For example, in Acts 16, Paul preached in a town called Philippi. Later, he sent them a letter that we now know as "Philippians" (just like I live in Tennessee so you call me a "Tennessean"). Almost every town or region mentioned in the books of Acts has a letter you can associate with it. It's great fun to read what happened while Paul visited the town (in Acts) and then see what he later wrote to them (in his letters) about the problems they faced and what advice he gave them.
In the book of Acts, you will also find Paul meeting new believers, such as Timothy in Acts 16:1. Paul later wrote Timothy two different letters, we call I Timothy and II Timothy.
These are just a few examples, for everone who ever wrote any part of the Bible had to be alive during some part of history. It's cool when you make these connections. They make for awesome Bible studies!