Which major event contributed to the spread of Christianity in the early centuries?

The spread of Christianity in the early centuries was significantly influenced by the persecutions under Nero and Vespasian. These persecutions, although suppressive, often resulted in increased visibility for the Christian faith. The suffering and martyrdom of early Christians captured the attention of many in the Roman Empire, leading to a deeper inquiry into their beliefs.

The strength and resolve displayed by Christians in the face of adversity served as a powerful testament to their faith, inspiring others to explore or convert to Christianity. Additionally, such trials fostered a strong sense of community among believers, which helped in the establishment and spread of the church across different regions. The narratives surrounding these persecutions became part of the early Christian testimony, leading to increased interest and discussion among non-believers.

While other events like the writing of the Nicene Creed, the legalization of Christianity by Constantine, and the establishment of monastic movements played important roles in the history of Christianity, it was the initial persecutions that catalyzed a much broader awareness and movement for the faith during its formative years.