Why did Christianity spread while Judaism did not?

Answer 1

God made a covenant with Abraham "I will be your God and you will be My people". As "God's people" the nation of Israel was to be a Godly nation, a light to the Gentile nations, showing them God's ways. But Israel failed to do this and they turned God's Law into a religious system of rules and regulations - Judaism.

Jesus came to call the nation of Israel to repent:

Matthew 15:24 But He (Jesus) answered and said, "I was not sent except to the lost sheep of the house of Israel."

But Israel rejected Jesus and He was crucified, the "lamb of God", a sacrifice for all sin. The way was open for all people to come to God on the basis of Christ being a suitable sacrifice for sin.

So God has replaced Judaism with a "new and living way", a new covenant based on the death of Christ. This is why Christianity has spread, God is revealing Himself to the Gentile nations through the death of Christ not Israel/Judaism.

When the "times of the Gentiles" has been fulfilled God will turn again to Israel.

Read Romans chapter 11

Answer

Politics, history and society did truly have an effect on the spread of these religions. Christianity, in its various denominations, was more easily assimilated after Constantine's victory. The Jewish people were effectively removed from Jerusalem by the Roman Empire and slowly spread throughout Europe. These populations were generally limited by economic and social statutes regarding where they lived and how they earned their living. Still, the beliefs of the Jews and the Christians-and the Muslims- intersect with Christianity until the coming of Jesus.

Answer 2

In the early centuries of the Common Era, Roman citizens began thinking about alternatives to their ancient pagan faiths. This brought about a rapid growth of 'mystery' religions, such as that of Dionysis-Osiris. However, there was also a growing interest in monotheism.

In those times, people who wished to follow monotheism had three important religions to choose from: Judaism, Christianity and Mithraism, and all were relatively successful in attracting converts. Judaism suffered from the disadvantage of insistence on adult circumcision. Mithraism suffered from the disadvantage of not accepting women as full participants in its religion. Christianity did not require circumcision and often sought to attract the women of a household, then using the women as allies to convert their husbands and other menfolk.

In the end, it came down to a single battle and a single Roman emperor. In a battle for supremacy as emperor, Constantine sought the allegiance of the Christians in the Roman army, while his opponent allied himself with Mithraism (although it also involved east-west allegiances). Constantine won the battle and gave considerable state support to the Christian Church. Within a century, Christianity had won many more converts and the emperor made the Orthodox-Catholic Church the state religion of the empire.