When was the birth of Christianity in Islam?

Christianity began more than 2000 years ago, when Jesus was born. It is difficult to say exactly when this occurred, since he was not born in the year 0; some historians believe he was born in 4 or 5 BCE. And there are scholars who question the use of his birth as the starting point for the Christian religion. Christianity began as a small sect within Judaism, and it separated from Judaism over the belief that Jesus was the messiah (Jews did not believe that the messiah had come yet).

The Christian religion emerged gradually, after Jesus was crucified and his followers began writing the stories (gospels) about his life. The books of the Christian bible (the New Testament) were compiled over a period of more than 100 years. Thus, Christianity began when it officially separated from Judaism and established its own holidays, customs, and rituals, as well as its own unique scripture. This process began about the year 45 of the Common Era.