This is a statement of faith that is the only ecumenical creed accepted as authoritative by the Roman Catholic, Eastern Orthodox, Anglican and almost all mainline Protestant churches. The creed was most likely issued by the Council of Constantinople in 381 AD, hence...
It was 325 A.D. at Nicea that the doctrine of the Trinity was rammed through by Athanasius (who in the future would use strong-arm tactics that would make a modern day mobster proud) in a Council that was overseen by the Emperor Constantine who, ironically enough,...