Right after the Ascension of Christ in 29 AD. The Apostles would have carried the message far and wide and start 1st century churches.
The first Christian communities outside of Jerusalem appeared in Antioch, Ephesus, Corinth, and the political center of Rome. The original church communities were founded by apostles and numerous other Christians, soldiers, merchants, and preachers in northern Africa, Asia Minor, Arabia, Greece, and other places. Over 40 churches were established by 100, many in Asia Minor.Paul was responsible for bringing the Christianity to new parts of the world such as Ephesus, Corinth, Philippi, and Thessalonica. By the end of the 1st century, Christianity had already spread to Rome and to various cities in Greece, Asia Minor and Syria. Major cities such as Rome, Ephesus, Antioch and Corinth served as foundations for the expansive spread of Christianity in the post-apostolic period. Christianity spread quickly throughout Asia Minor.
Paul
The Christian belief comes from God, but specially Jesus Christ(that is where the word came from). The "Christian belief" is that Christ died for our sins on the cross and accepting him as our savior.
Jews living outside Israel. Generally the spread of any people from their original homeland
For 13 years the (what you call) christians spread the teachings to Judeans only, then to the lost tribes of the house of Israel, which was able to include anyone outside of Judah as well.
By Israel filling up with Jewish immigrants.
The spread in belief of one God is called monotheism. This was made possible by Abraham.
The policy of the US toward the Soviet Union after WWII was shaped by a belief that the Soviets intended to spread Communism throughout the world.
It spread by Christian missionaries looking for a new place to spread their religion
the pope made it a point to visit every country to spread goodwill and christian love. this year he was on a world tour and decided to stop in Israel
Jesus' disciples were first called Christians at Antioch, then in Syria and now in Turkey. But Jesus, whom Christian disciples worship, was born in Bethlehem and crucified and died at Jerusalem in Israel. But really, Christianity was and is founded in Heaven!
Charlemagne was a devout Christian and was a strong supporter of the Catholic Church. He worked to spread Christianity throughout his empire and promoted the Christian faith through education and religious reforms.
Through truth.