THE POSSIBILITY
3RD CENTURY PAGAN MONOTHEISM
While the concept of pagan monotheism is something of an anachronism since monotheism as a term wasn’t coined until the 1600s, the concept of raising one god among others in polytheistic religions, such as Roman Paganism, was not uncommon. The idea of henotheism was gaining some ground in Constantine’s time, which might suggest a religion with an all-powerful god was being sought. One of the earliest examples is the Egyptian pharaoh Akhenaten (1353-1336 BCE) and, obviously, Judaism was already a powerful faith by 306 CE. The presence of images of the Greek god Helios in some Jewish synagogues dating back to the 3rd century points towards efforts to depict complementary religious ideas that could sit together harmoniously.
325 CE RISE OF ARIANISM
One of the important interventions of Constantine was in regards to the Arian Heresy. Arius, a minister in the Church in Alexandria, had proposed a delineation of the Holy Trinity that made God a singular being, indivisible and above Jesus. This was heavily opposed by many sectors of the Christian Church who held firm to the concept of that God and Jesus were equal. When Constantine convened the Council of Nicaea it was precisely to tackle this question and to find a consensus, which in this instance decided against Arius. But without Constantine’s influence and his power to enforce the ruling of the council, it’s possible that Arianism could’ve gained ground and a stronger offshoot of Christianity may have been formed.