The import causes for the spread of Christianity were:
1. Personality of Jesus: The simplicity of Jesus attracted common people to him. His appeal towards poor, sinners and sufferers and his spiritual power helped in the spread of religion.
2. Simple principles: Jesus’ principles like fraternity, compassion, forgiveness, and faith in the Kingdom of Heaven – all these made Jesus popular among the poor and the slaves.
3. Role of Apostles: The 12 apostles played a dominant role in spreading Christianity by popularizing the principles of Jesus. Among them St. Peter and St. Paul are important. St. Peter founded a Church at Rome and became the first Pope to spread Christianity in Rome and Asia Minor. St. Peter was executed by Nero the Emperor of Rome which made him a martyr. St. Paul became the second Pope.
4. Role of Church: The Church became the chief institute for the preservation and propagation of the faith. People believed in Church as a way to Heaven and the pope as the representative of God. Despite persecutions, Christianity gained popularity.
5. Role of Constantine: The persecution of the Christians stopped when Constantine became the Emperor of Rome. He built a new city called Constantinople and dedicated it to virgin Mary. He issued the Edict of Milan, which made Christianity a legal religion in the Roman Empire and gave permission to the Christian missionaries to spread Christianity in the East. Under Emperor Theodisius in the 4th century C.E., Christianity became the state religion.
