The history of the early christian church is found in what biblical book

The history of the early Christian church is found in the Acts of the Apostles.

Explanation:

The Acts of the Apostles is the fifth book of the New Testament in the Bible. It comes after the four gospels. It is a common belief that it was written by the Macedonian physician Luke, the author of the Gospel of Luke. The book focuses on the beginning and spread of the Christian movement and the Christian message. It is based on the early Christians' experiences on Pentecost, focusing in particular on Paul's activities in the Mediterranean, and how Christianity spread from being a purely Jewish phenomenon to a movement that included other peoples.