The purpose of a creed is to act as a yardstick of correct belief.  It was hoped that by memorizing this summary of the faith, lay people without extensive theological training would still be able to recognize deviations from orthodox doctrines based on the Bible as interpreted in Christian Tradition.

The Nicene Creed, both in its original and revised formulas, is an implicit condemnation of specific beliefs as errors. Thus, as different variations in Christian belief evolved in the fourth century and were perceived as threats, new phrases would be needed. The original intent was to use only Biblical language, but Arians could agree to all such language, so this solved nothing. Eventually the delegates at Nicaea would resort to extra-Biblical to clearly define the doctrine of the trinity.

 The original Nicene Creed of 325

The original Nicene Creed was first adopted in 325 at the First Council of Nicaea. At that time, the text ended after the words “We believe in the Holy Spirit”, after which an anathema was added. This is the statement of condemnation of any who do not accept the trinitarian statement of the creed. This anathema would be dropped from the creed of 381.

  The Nicene Creed of 381

The second Ecumenical Council in 381 added the section that follows the words “We believe in the Holy Spirit”;  hence the name “Nicene-Constantinopolitan Creed”, referring to the Creed as it was after the modification in Constantinople The third Ecumenical Council reaffirmed the 381 version, and decreed that “it is unlawful for any man to bring forward, or to write, or to compose a different faith as a rival to that established by the holy Fathers assembled with the Holy Ghost in Nicaea.”

 

Comparison between Creed of 325 and Creed of 381

The following lists display side by side the earlier (325) and later (381) forms of this Creed in the English translation, which indicates by brackets the portions of the 325 text that were omitted or moved in 381, but uses no typographical mark to indicate what phrases, absent in the 325 text, were added in 381.

First Council of Nicaea (325)

First Council of Constantinople (381)

We believe in one God, the Father Almighty, Maker of all things visible and invisible.

We believe in one God, the Father Almighty, Maker of heaven and earth, and of all things visible and invisible.

And in one Lord Jesus Christ, the Son of God, begotten of the Father [the only-begotten; that is, of the essence of the Father, God of God], Light of Light, very God of very God, begotten, not made, being of one substance with the Father;

 

And in one Lord Jesus Christ, the only-begotten Son of God, begotten of the Father before all worlds, Light of Light, very God of very God, begotten, not made, being of one substance with the Father;

by whom all things were made [both in heaven and on earth];

by whom all things were made;

who for us men, and for our salvation, came down and was incarnate and was made man;

who for us men, and for our salvation, came down from heaven, and was incarnate by the Holy Spirit of the Virgin Mary, and was made man;

 

he suffered, and the third day he rose again, ascended into heaven;

he was crucified for us under Pontius Pilate, and suffered, and was buried, and the third day he rose again, according to the Scriptures, and ascended into heaven, and sits on the right hand of the Father;

 

from thence he shall come to judge the quick and the dead.

from thence he shall come again, with glory, to judge the quick and the dead;

 

 

whose kingdom shall have no end.

And in the Holy Spirit.

And in the Holy Spirit, the Lord and Giver of life, who proceeds from the Father, who with the Father and the Son together is worshiped and glorified, who spoke by the prophets. In one holy catholic and apostolic Church; we acknowledge one baptism for the remission of sins; we look for the resurrection of the dead, and the life of the world to come. Amen.

 

[But those who say: ‘There was a time when he was not;’ and ‘He was not before he was made;’ and ‘He was made out of nothing,’ or ‘He is of another substance’ or ‘essence,’ or ‘The Son of God is created,’ or ‘changeable,’ or ‘alterable’ — they are condemned by the holy catholic and apostolic Church.]