On 19 June 325, the delegates at the Council of Nicea agreed to a statement of belief which has come to be known as the Nicene Creed. This statement expresses the core doctrine and dogmas of the Catholic, Lutheran, Anglican, and the Eastern and Oriental Orthodox churches. One tradition states that the Nicene Creed was originally formulated by Saint Athanasius.

One of the primary reasons for the Nicene Creed was to deal with the Arian heresy which denied that Son was truly divine as the Father is divine. Therefore, the Nicene Creed includes phrases which emphasis an equality between the Son and the Father – “begotten not made”, “true God from true God”, “light from light”, “one in being with the Father”.

The Nicene Creed is different the from the modified Nicene-Constantinopolitan Creed recited every Sunday and solemnity in the Roman Catholic Church. For example, the Nicene Creed expresses the words “I believe in the Holy Spirit”, whereas the Constantinopolitan Creed adds the words “who proceeds from the Father, who together with the Father and the Son is worshiped and glorified, who spoke through the prophets.” Later the Roman Catholic Church also added the filioque or the words “and the Son” to the Constantinopolitan Creed i.e. “who proceeds from the Father and the Son, who together with the Father….”*

For more on the Nicene Creed and how it compares with the Nicene-Constantinopolitan Creed

*While this addition has caused a great deal of controversy between the Orthodox and Catholic Churches, interestingly enough it was originally added to deal with the Arian heresy in Spain – stressing that the Spirit proceeded from the Son as the Spirit proceeded from the Father was a way of emphasizing that the Son was equal in divinity to the Father.