It wouldn’t only be one new denomination, of course. It would be four or six or more (even if some were much smaller in membership than the others.)
The theological distinctions between unitarianism (so-called), modalism and trinitarianism, are very serious–and that doesn’t even count some major distinctions about the nature of the Son and his relationship with God and creation among unitarians. We try here at EU to be accomodating to modalists and unitarian Christians, so long as they’re polite in discussion (ditto trinitarians ), but the original leadership had to take a strong stand on one kind of theology in order to have a base to work from (which is why the founding members are mostly trinitarian and why they invited trinitarian guest authors like myself, Robin and Tom, to help originally give theological shape to the board)–and more to the point, this isn’t a church for worship. We can all agree to worship the Father; the problem comes in whether or not we’re supposed to be worshiping the Son and the Spirit (and/or seeking salvation from them), and if so how and to what degree.
So that’s three or even more distinct denominations right there. And that’s before we get to the question of God’s wrath: does God do no wrath at all?–no wrath anymore? (and is that anymore after Christ, or after the Temple?)–wrath but only in this life, not in the Day of the Lord to come?–wrath in the Day to come, but God will surely succeed in saving all souls from sin? (and does all souls include demons, or do demons not exist to be saved in the first place?)–wrath in the Day to come, but we can’t be sure God will eventually succeed in saving all souls? (which would still be universalism so long as God is persistently acting to do so)–wrath in the Day to come, and we can be sure God never will succeed in saving at least some souls from sin (which would still be universalism so long as God still eternally acts to do so)? All these positions could potentially (and even actually?) be multiplied by the number of Christologies.
And that doesn’t even count theologies like Von Balthasar, or the identical Protestant positions recently discussed here (exemplified by Bro. Punt), which go the next step toward hopelessness by affirming that God may or surely will give up acting to save everyone sooner or later (i.e. Arminianism) but which wants to call itself “biblical universalism” by virtue of God’s original intention and action (to save?–or only to provide a possibility for the soul to save itself??) in universal scope, as well as by virtue of at least a nominal wave of assent in the direction of biblical testimony to God’s universal persistence (though this ends up being denied after all). But those people think they can claim “biblical universalism” distinct from an Arminianism category by acknowledging the persistence a little more than Arms generally do while still denying it really means persistence.
We have to take doctrines other than universalism seriously, because if we don’t then, well, there’s already a denomination that doesn’t take any doctrine seriously other than universalism (in the shallowest broadest sense possible at that): the Unitarian Universalists. Who aren’t even doctrinally unitarian in any way!! They may be very nice people, but I wouldn’t go there to worship (I would sooner go to a real unitarian church to do so–I would sooner go to a Mormon church to do so!); and I have not yet met one vocal member here who thinks the UUs are right to be doing what they do in the way they treat theology and truth.
But taking doctrines seriously means making decisions about what to believe, in one way or at least one set of ways and definitely not in other ways.
Sure, I could start up a new universalist Christian denomination tomorrow. But I would start it up in regard to beliefs other than universalism that I not only consider true but important–beliefs that will conflict with what other Christian universalists consider to be both true and important. And if someone else wanted to start up a new universalist denomination, I would think seriously about what kind of universalism they were preaching (or even if I could honestly consider it universalism), and about what other theological doxologies (right-representations of God) they were preaching, and whether I could agree with that, and if so how far (or not), before I joined that congregation.
What I’m saying, is that it isn’t as simple as “forming universalist congregations”. I’m loath to bring even one more denomination into the world (even though I think about doing so sometimes). Would bringing another six or dozen or twenty denominations into the world really be the best way to be salt and light and leaven in the dough?
I have doubts about that.