Scholars agree that Constantine's adpotion of Christianity contributed to the downfall of the Roman Empire, but are in disagreement as to whether it was the major single cause, or one among several causes.
The Roman Empire was already heavily taxed, but the need for much higher taxes in order to support the Christian Church was to remove incentive for the middle classes, resulting in a decline in prosperity and, of course, a reduction in the tax base. The Empire could not continue to sustain a military machine capable of withstanding external threats.
The Christian Church opposed knowledge that did not contribute to the needs of the Church. books were burnt and eventually even the great Library of Alexandria was burnt down. Many ancient texts only survived because they had spread beyond the limits of the Roman Empire, and are now known to us because the Muslims returned them to Europe. With the loss of knowledge and the decline in education came a loss of technology. Infrastructure was neglected and soon was beyond the ability of the empire to repair and maintain. There was to be no expansion in technological capability for over a thousand years.
Christianity
There was only one Roman Empire. Moreover, the Roman Empire did not study Christianity. An empire cannot study. The Roman Empire was where Christianity spread from Judea (which was a part of the Roman province of Syria). Both Catholic and Orthodox Christianity developed in the Roman Empire. Originally the were called Latin or Western Christianity and Greek or Eastern Christianity respectively. The former was the dominant form of Christianity in the western part of the Roman Empire and the latter was the dominant form of Christianity in the eastern part of this empire. There were also dissident Christian doctrines and sects.
The emperor Theodosius I declared Christianity to be the official religion of the Roman empire. In fact, he made Christianity mandatory for all.
Christianity did not easily spread through the Roman Empire. See the related question, "How did Christianity spread throughout the Roman Empire?"
Christianity developed from a religion among a small group of Jews (who lived in Judea, which was part of the Roman Empire) into a mass religion in the Roman days. It spread around the Roman Empire. It became state religion. Catholic Christianity and Orthodox Christianity developed during the Later Roman Empire. They were originally called Latin or Western Christianity and Greek or Eastern Christianity respectively. The former was the main form of Christianity in the western part of the Roman Empire and the latter was the main form of Christianity in the eastern part of the Roman Empire.
Christianity
There was only one Roman Empire. Moreover, the Roman Empire did not study Christianity. An empire cannot study. The Roman Empire was where Christianity spread from Judea (which was a part of the Roman province of Syria). Both Catholic and Orthodox Christianity developed in the Roman Empire. Originally the were called Latin or Western Christianity and Greek or Eastern Christianity respectively. The former was the dominant form of Christianity in the western part of the Roman Empire and the latter was the dominant form of Christianity in the eastern part of this empire. There were also dissident Christian doctrines and sects.
To this day, historians argue over what caused the Roman empire's downfall.
Roman empire.
The emperor Theodosius I declared Christianity to be the official religion of the Roman empire. In fact, he made Christianity mandatory for all.
After the Emperor Constantine converted to Christianity, that became the official religion of the Roman Empire.
The Roman Empire made Christianity the official religion of the Empire, and 'encouraged' the peoples it conquered to convert.
the religon that originated in the roman empire is Christianity
Christianity did not easily spread through the Roman Empire. See the related question, "How did Christianity spread throughout the Roman Empire?"
Christianity developed from a religion among a small group of Jews (who lived in Judea, which was part of the Roman Empire) into a mass religion in the Roman days. It spread around the Roman Empire. It became state religion. Catholic Christianity and Orthodox Christianity developed during the Later Roman Empire. They were originally called Latin or Western Christianity and Greek or Eastern Christianity respectively. The former was the main form of Christianity in the western part of the Roman Empire and the latter was the main form of Christianity in the eastern part of the Roman Empire.
Christianity
Christianity started in Judea, which was part of the Roman Empire. The Apostles and other preachers travelled around the Roman Empire (mainly the eastern part, in the eastern Mediterranean). A Christian clergy headed bishops developed. Paul the Apostle created the foundation of the Christian doctrine. Other important theologians, who are called the 'Fathers of the Church' developed the Christian doctrine further. Christianity developed into two main forms: Greek or Eastern Christianity, which was the main form of Christianity in the eastern part of the Roman Empire, and Latin or Western Christianity, which was the main form of Christianity in the western part of the empire. Later they came to be called Orthodox and Catholic respectively. There were 'Fathers of the Church' in both Greek and Latin Christianity. There was also a number of dissident Christian doctrines. The most important of these was Arian Christianity, which was quite popular around the Roman Empire. Latin and Greek Christianity became the official religion of the Roman Empire thanks to their endorsement by the emperors of the later Roman Empire and the persecution of dissident Christian doctrines and pagan religions by some of these emperors.