By the late 3rd century AD Christianity had become the major religion of the Roman Empire. Prior to this, the Roman religion was the most important one because it was the state religion. However, peoples in the provinces retained their old religions they had worshiped since before the Roman conquests.
Christianity became the official religion of the empire during the reign of emperor Theodosius I.
The state religion of the Byzantine Empire, during the entire time we refer to it by that name, was Christianity.
The dominant religion in the Roman Empire was the Roman religion until Christianity became the dominant religion.
Roman Catholicism
Islam became a rival of Christianity in the Byzantine Empire.
The religion in the Byzantine Empire was Christianity. This was the furthest extent of Christianity to the East. Further East were Islam and other major religions during this time. Christianity became the main religion because of Justinian's influence on the people.
Christianity became the official religion of the empire during the reign of emperor Theodosius I.
HINDU
Because it became (perhaps by divine design) the single, state religion of one of the greatest and long lived early empires - the Roman empire.
An idea which had a major effect was the Christianity's idea that Christ was the son of god and that he died to redeem humanity. In the Later Roman Empire Christianity became the state religion of the empire and many people in the empire converted to Christianity, which was a major religious change.
The state religion of the Byzantine Empire, during the entire time we refer to it by that name, was Christianity.
Through most of their history the ancient Romans had their own religion: Roman Religion. In the Later Empire Christianity spread in the Roman Empire, was endorsed by the Roman emperors and became state religion.
Christianity was the major religion that was born during a time when the Roman Empire was near its height.
Christianity was the major religion that was born during a time when the Roman Empire was near its height.
The dominant religion in the Roman Empire was the Roman religion until Christianity became the dominant religion.
Byzantine Empire is a term which has been coined by historians to indicate the eastern part of the Roman Empire after the fall of the western part. The people in question did not even know this term and called their empire Roman Empire. Christianity spread though the eastern part of the Roman Empire before the fall of the western part. Christianity developed into two main forms, the Latin or Western Church and the Greek or Eastern church. The former was the main form of Christianity in the western part of the empire and the latter was the main one in the eastern part. Later they came to be called Catholic and orthodox respectively. Both these branches of Christianity became state religion in 380. Therefore,what we now call Orthodox Christianity was already the religion of the eastern part of the Roman empire before the Byzantine period.
AnswerEmperor Constantine made Christianity an official religion of the empire about 312 CE. It became the official religion of the Roman Empire in the 380s CE.