The first Christian history book is a collection of writings that span more than 1,500 years and were written by about 40 different authors. The first 3/4s of the book contains the history, culture and experiences of the Jewish people. That portion is called the Old Testament. Since the first Christians were Jewish, that was their first Bible.
The next section, called the Gospels, contains the history of Jesus and His life on earth. It starts out by tracing His genealogy through Old Testament people.
Next comes Acts which is the history of the first Christians and their encounters with the risen Jesus until about 60 AD. After that follows the Epistles, letters written by some of the earliest Christ-followers.
The book ends with Revelation. It was written by the last of Jesus’ original 12 disciples, John (who also wrote the Gospel of John and the Epistles of 1, 2, and 3 John). All the other original 12 disciples had been murdered for their faith in and obedience to the living Jesus. John was exiled to an island called Patmos. There John had an extended vision of the risen, glorified Jesus and wrote it down.
The living Jesus showed John 7 letters written to 7 communities of Christians that gathered in 7 different cities. He praised and corrected those communities and told them to hear what the Spirit is saying. To the Christ-followers that met in the city of Ephesus, Jesus told them that they had “left their first love.” Then John described many amazing, heart-stirring, and confusing scenes that Jesus showed him in the vision.
Since that time, the history of Christianity has been the story of people experiencing the risen Jesus and following him with fire in their heart. It has also been the story of people losing their first love for Jesus and institutionalizing Him with religious organizations and programs. It’s the history of how people who had lost their first passion for the risen Jesus (or never had it) have run religious organizations. But it’s also how Christ-followers overflowing with first love for Jesus have reformed parts of those organizations and/or broken away from them to freely follow and obey the risen Jesus.
A man named Eusebius (260-339 AD) is often called the “Father of Church History,” because he wrote a book about Christian history up to the time of Roman Emperor Constantine. However, Dr. Luke, the author of the Bible book of Acts should really have that title.

“first love for Jesus”……..”to freely follow and obey the risen Jesus” .. amen!