Nicene Christianity includes those Christian denominations that adhere to the teaching of the Nicene Creed,[1] which was formulated[2] at the First Council of Nicaea in AD 325 and amended at the First Council of Constantinople in AD 381.[3] It encompasses the vast majority of today's Christian churches.
In the most common sense, "mainstream" refers to Nicene Christianity, or rather the traditions which continue to claim adherence to the Nicene Creed.
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