How did Christianity get spread around so fast?

The rapid spread of Christianity after the first century AD is an amazing story. Christianity is basically a Jewish sect that emerged in the Palestine region and then split off and went on its own. At first this new Christian sect adhered to Jewish religious practices like circumcision and honoring the Sabbath, but after it broke away and spread to the Roman colonies around the Mediterranean, these practices faded, mostly because more and more non-jews were coming into the ranks. Keep in mind that Jesus, the founder of Christianity, was a Jew who grew up learning about Jewish customs and religion. He read the scriptures and commented on them in the synagogue. He obviously was not only familiar with the scriptures but he had been circumcised and observed the Jewish religious practices. And, his apostles and disciples did the same. Remember that the apostles and disciples were preaching to what they called gentiles, basically non-Jews.

The main reason that Christianity spread so quickly is because by the first century AD the Roman Empire had expanded to take over most of the known Western world and some of the Eastern world as well. Roman citizens regardless of origin or ethnicity could travel anywhere in the Roman world without trouble. This made it easy for Jesus' apostles and disciples to spread the gospel, meaning the good news, in this case the good news of Jesus' resurrection and ascension. We see some of this evangelic work in the book: Act of the Apostles. This book has been attributed to Luke the Evangelist and was written in Greek around 80-90 AD and it relates the conversion of Paul, who was instrumental in spreading Christianity all over the Roman world. Most of the providences mentioned in the Acts were under Roman control: Jerusalem, Antioch, Samaria, and Rome. Many of these evangelical events were related in Paul's epistles.

Keep in mind that there were many religious cults during the early centuries AD. Mithraism, Zoroastrism, cult of Dionysus, and, of course, the fact that Augustus considered himself to be the son of a god. Early Christians rejected the idea of worshiping the Emperor and were persecuted for this glaring omission.

One of the tricks that early Christians did to help attract followers was to move things like the celebration of Christ's birth to a Roman Festival of the Winter Solstice. It also helped that the Emperor Constantine made Christianity the state religion. By the fall of the Western Empire in 476 AD Christianity was in a position to take over both culturally and politically. Eventually, this expansion of Christianity became ugly, as in the case of the Crusades (the attempts to take back Jerusalem from the Muslims) and the exercise of absolute power in the Holy Roman Empire.

Another reason that Christianity spread so quickly in the early centuries is because it gave women status and equality. Unfortunately, when the church became politicized this female advantage evaporated. Men of that age were not about to give women any authority or status. This misogyny is slowly beginning to be eradicated, but it's a long uphill battle. Someday it will be.

Thanks for reading.