One of the indications of the way in which a phrase from the Nicene Creed would have been ‘heard’ in the ancient Church is to look at other sources that speak to the same issues the Creed addresses. When it comes to ‘one baptism for the remission of sins’, consider the following inscription on a baptistry in the Lateran Basilica, dating from the mid-fifth century, in the time frame that the Niceno-Constantinopolitan Creed was formulated.
Here a people of godly race are born of heaven;
the Spirit gives them life in the fertile waters.
The Church-Mother in these waves bears her children
the virginal fruit she conceived by the Holy SpiritHope for the kingdom of heaven, you who are reborn in this spring,
for those who are born but once have no share in the life of blessedness.
Here is to be found the source of life, which washes the whole universe,
which gushed from the wound of Christ.
Sinner, plunge into the fountain to wash away your sin.
The water receives the old man, and in his place makes the new man rise.
You wish to become innocent, cleanse yourself in this bath,
whatever your burden may be, Adam’s sin or your own.
There is no difference between those who are reborn; they are one,
in a single baptism, a single Spirit, a single faith.
Let none be afraid of the number of the weight of their sins:
those who are born of this stream will be made holy.
That is a remarkable theology of baptism and new creation, forgiveness and union with Christ and his Church.
Biblical Horizons 
I have used this phrase of the Nicene Creed to show that it is not a new or even heretical doctrine.
I have wondered about this for sometime. Is this consistent with a Reformed view of baptism? Whenever we confess the creed, are we really confessing the faith of the creed and the ones that produced it?
A very good question.
Not even Moses could divide the waters as much as Christians have divided in the past several centuries over the meaning and mode of baptism. I love the old story about the Episcopal Priest and the Baptist Pastor who were very good friends and decided to have a ‘friendly’ debate on the subject in front of the gathered congregations. The only rule was that each debater could only use Scripture quotes. The Priest went first and said, “Suffer the little children to come to me and forbid them not.” The Baptist then rose and said ferociously, “Og, King of Bashan and all his hordes!”. The Priest looked at his colleague incredulously and asked, “What does that verse have to do with baptism?” “About as much as yours did”, replied the Baptist.
We Reformed would do well to heed Calvin that the sacraments are savingly efficacious only because of the accompanying ministry of the word and the Spirit. This one inscription helps us ‘hear’ an ancient voice (not the lone ancient voice mind you!). I hardly need to note that there were many – and stiil they persist – that have a rather bizarre view of the rite, a perfunctory ‘when the water goes on the grace goes in’ approach. But the baptism of Simon in Acts 8 reminds us that while water and Spirit are so often seen together in the pages of Scripture, not everyone in the water is also in the Spirit.
That said, we should not fall prey to the other extreme and end up in a Zwinglian ditch. The Bible teaches that God uses these wonderful gifts we call ‘sacraments’ in powerful ways. There certainly isn’t room here for a treatise on sacraments , but there is no shortage of work already done on this that is helpful. Tolle Lege!
The inscription referred to alludes to a catena of Scripture references.
born of heaven (John 1:12-13; James 1:17)
gift of the Spirit with baptism (Acts 2:38)
church as mother (Gal. 4:26)
reborn unto life (John 3:1ff)
baptism as washing (Acts 22:16)
one baptism, one Spirit, one faith (Eph. 4:4-6)
It may be something of a poetic expression and application of Biblical baptismal faith, but it is simply a repetition of various Bible verses.
Nothing really extreme about that!