Its roots are in Judaism and its earliest followers were Jews, but it originated in the life of Jesus Christ. Jesus came out of the Jews and was an extension of the providence of that people and God's plan. Jesus didn't give a law, but the standard resides in and comes from Him. People had to learn to think universally, and this was the seedbed on which Christianity grew.
When Jesus died, His apostles acted as though He were still alive and followed Him with an unchanged intensity. They spread Christianity throughout the Roman Empire, and the New Testament is mostly composed of letters sent to the localities where they evangelized.
They formed the system of Christianity and ways of worship, which are standard in any liturgical church (Catholic, Anglican, Lutheran, and Orthodox).
(Hillsdale College - Ancient Christianity)
Favorable Circumstances
- Jewish Religion, Judaism (concept of a Messiah, remarkable births, and the anticipated birth of God Himself)
- Greek language and culture (Platonism, the vocabulary to describe Christian concepts like logos, ousia without allowing for syncretism)
- Roman unity and law