What does it mean to profess the Nicene creed? As a logical and logistical matter, it isn’t even possible to profess the Nicene creed, for there’s no one Nicene creed to profess. Rather, you have to make an initial choice between two different versions of the Nicene creed: the Eastern and the Western.
The Western edition contains the famous or infamous (depending on your viewpoint) filioque clause, whereas the Eastern edition, which represents the “original” version, does not.
The filioque is generally dated to Toledo III in 589, although there’s a text-critical question regarding our extant MSS. Did the original canon include the Filioque?
However, the theology underwriting the filioque antedates Toledo. It has antecedents in Hilary of Poitiers (4C) and Marius Victorinus (4C). It especially reflects the Triadology of Augustine.
The Western edition is the default edition for Protestants and Roman Catholics. I believe that’s the edition which is customarily recited in Roman Catholic and Protestant churches.
If you’re a high churchman (e.g. Roman Catholic, Anglo-Catholic, Eastern Orthodoxy), your authoritarian ecclesiology commits you to a take-it-or-leave-it attitude towards the Nicene creed. If, on the other hand, you’re a low churchman, you’re at liberty to affirm as much as you think is correct.
From what I’ve read, the Eastern orthodox object to the filioque on two basic grounds:
i) They raise an ecclesiastical objection. They don’t think the Western church had the authority to unilaterally amend the Nicene creed. The Nicene creed was promulgated by Constantinople 1, and only another ecumenical council has the authority to revise the Nicene creed.
Of course, that objection shifts the question to whose church has the authority to revise the Nicene creed. Obviously Roman Catholics do think their church has that prerogative.
ii) They also raise a theological objection. They think double procession is ditheistic, for it introduces a second originating principle into the Trinity.
Whether that’s true is a matter of interpretation. For instance, I believe that Augustine still regarded the Father as the primary and ultimate source of the Son and the Spirit alike. So it may be a difference of emphasis.
Conversely, the filioque may have been added to close the door on Arianism, by giving the Son a constitutive role in the intratrinitarian existence.
To some degree the Eastern and Western versions of the Nicene creed reflect different models of the Trinity. To somewhat oversimplify the difference, the Eastern begins with the Father as the source of the (other) persons whereas the Western begins with the divine nature as the source of the persons.
The whole debate is like Trinitarian plumbing. Is the Father the faucet that channels the Son and Spirit through two separate pipes, or does the Father channel the Son through one pipe, while the Son diverts the stream through another pipe to channel the Spirit?
In my opinion, both models of the Trinity trade on implicitly mechanical metaphors which are unsuited to a timeless, spaceless God.
In any event, we need to ground our doctrine of God in his biblical self-revelation, rightly interpreted.