Final answer:
The role of Christianity in the development of Rome was transformative, leading to social and cultural changes by its spread and eventual establishment as the state religion. It redefined religious practices, influenced the architecture and urban landscape with the construction of churches, and was thought of as a divine influence on the Empire's fortunes.
Step-by-step explanation:
Christianity played a pivotal role in the transformation of Roman society, particularly with its unique religious experiences and customs. Initially, Christians were a diverse group whose practices, such as the lack of animal sacrifices and refusal to worship Roman emperors, set them apart from the mainstream religious customs. This monotheistic faith, which actively sought new converts, threatened the hierarchical nature of Roman society and at times faced severe persecution, such as under Emperor Nero in 68 CE.
However, the spread of Christianity and its eventual endorsement by Roman emperors like Constantine led to significant social and cultural changes. It promoted communal identity through prayer, communal feasting, the calling of each other as "brother" and "sister," and the practice of baptism. By the fourth century, Christianity became the official religion of the Roman Empire under Emperor Theodosius I, which resulted in the redirection of resources to the construction of churches, and the decline in traditional polytheistic worship.
Furthermore, the fall of Rome was interpreted by Christians of the time as divine retribution for polytheism and heresy, while remaining polytheists saw the rise of Christianity as a factor in Rome's decline. The true causes of Rome's fall, however, appear to be more linked to military defeats and external threats. Nonetheless, the establishment of Christianity as the state religion and the support of emperors in building massive church edifices, like the Basilica of St. Peter, indicate the profound impact Christianity had on Roman society and culture.