The Council of Nicaea
Constantine is not prepared to tolerate divisions within the Christian Church, a threat to Roman stability that he regards as "formidable as any war or battle". An ecumenical ("world –wide") council of church leaders is convened at Nicaea to debate Arianism; a popular religious doctrine, which holds that Jesus Christ ("the Son"), is inferior to God ("the Father").
The Council counters Arianism with the Nicene Creed, a theological formulation which includes the statement that the Son and Father are of the same substance and therefore equal.
Although the Council apparently 'solves' the problem of Arianism, the heresy continues to exist and gain many adherents over the next two centuries, including some of Constantine’s successors