- Polytheism: predominant religion, with worship of many gods. Major deities included Jupiter (king of the gods), Juno (queen of the gods), Minerva (goddess of wisdom), Apollo (god of music, poetry, and healing), and Mars (god of war).
- Emperor worship: Romans worshiped the emperor as a divine figure. They believed that the emperor was chosen by the gods to rule and that he had divine power and authority.
- Mystery religions: These were private, initiatory religions that promised personal salvation and immortality to their followers. Some of the most popular mystery religions included the cult of Mithras, the mysteries of Eleusis, and Christianity.
- Christianity: Christianity began as a small sect of Judaism in the 1st century CE. It quickly spread throughout the Roman Empire and eventually became the dominant religion. Christianity emphasized monotheism, belief in Jesus as the son of God, and the importance of love, compassion, and forgiveness.
After the collapse of the Roman Empire:
- Spread of Christianity: Christianity continued to spread throughout Europe after the collapse of the Roman Empire. It became the dominant religion in most Western European countries, and its teachings and values influenced European society and culture.
- Monasticism: The rise of monasticism was another significant religious development of the post-Roman era. Monasteries were communities of men or women who lived a religious life apart from the world. Monasticism played an important role in preserving and transmitting Christian teachings and culture, as well as in providing education and social services to the community.
- Rise of saints: The cult of saints became popular during the post-Roman era. Saints were individuals who were believed to have lived holy lives and to have special powers of intercession with God. People often prayed to saints and sought their assistance in times of need.
- Relics: The veneration of relics, or the physical remains of saints, also became popular during this time. Relics were believed to possess miraculous powers, and they were often sought after by pilgrims and religious communities.
- Religious conflict: The post-Roman era also witnessed periods of religious conflict and persecution. The most notable example of this was the conflict between Christians and pagans, which resulted in the suppression of paganism and the establishment of Christianity as the dominant religion in Europe.