I have eight relatives who at one time or another attended a Unitarian Universalist church and who are on Facebook. A quick polling of what their info pages say about their "religious views" gives the following answers:
2 list Unitarian Universalist (or some combination of those two words).
2 have the field blank or not viewable to me, which would be understandable given that I do things like this.
1 says "atheistic jew."
1 says "loving kindness."
1 says "Peace and Social Justice."
1 says "Aid to and support of the widows, the children, and the outcast."
Of these eight, I think two are members of Unitarian Universalist churches--one who lists UU and one who doesn't. Most of the others attend from time to time, but not regularly enough to consider themselves members, and mostly when visiting a relative who is church-going. So this shows that not everyone who calls themselves a Unitarian Universalist is a member of a church, and, conversely, not everyone who is a member of a church labels themselves Unitarian Universalist.
Of course, we've long known this sort of dynamic as a denomination. The Wikipedia article on Unitarian Universalism, for example, says that in the 2001 Census report, 629,000 people listed themselves as Unitarian Universalist, but in 2002 the UUA listed 214, 738 members. Obviously there are a lot of people who call themselves Unitarian Universalist but don't belong to a church.
Can you be a Unitarian Universalist without belonging to a church? I've heard it argued very eloquently that you can't. There's a certain logic to this. Since we're non-creedal, you don't become a Unitarian Universalist by subscribing to a set of beliefs. How do you become a Unitarian Universalist? By attending a church, by covenanting with us, by engaging in our dynamic living tradition. If you're not actively engaged with Unitarian Universalism as a religion through some relationship with one of our institutions, what makes you call yourself a Unitarian Universalist? Obviously those words mean something to those other 400,000 people, however, that goes beyond membership to a sense of their religious identity.
As a religious professional, obviously I choose to be a Unitarian Universalist who is a member of a church. However, I did go through four years of college wherein I didn't attend church but still very much called myself a Unitarian Universalist. So I know something about where that comes from. However, I guess I'm getting old now, because I have trouble remembering that perspective.
Obviously we don't want those 400,000 people, including at least one of my relatives, to stop calling themselves Unitarian Universalist. What we want is to know how to bring them back into membership in our churches, where obviously they at one point held some sort of connection that is still meaningful to them today.
I admit to being at something of a loss as to how to draw them back.
The workshop I attended at GA on recent trends in religious life, based on a Pew Forum study, pointed to some trends that help explain this. It's worth noting that of those eight relatives of mine, five are Generation X or Millennials, and none of those list Unitarian Universalism, even though one attends church. Of the Boomer Generation, two of the three list Unitarian Universalism, even though one does not attend church. This fits very much with what I'm learning about trends, wherein for Xers and Millennials, denominational identity is not only not as important, it's really a negative. Some of our trendier young-adult-focused churches, like Micah's Porch and Wellsprings reflect this, with a lack of denominational branding. So does our Standing on the Side of Love campaign. You have to look deep into these three webpages to find UU in the small print. And this kind of approach does seem to be working with young adults who despite their lack of interest in institutions, have a growing need for connection, community, and spirituality. They're the growing "Spiritual but not Religious" group, and we have something that can really address this, if we can leave some of our branding aside.
I'm a GenXer, so I understand a lot of these recent trends: the increased focus on parenting, the increased use of technology, the larger percentage of non-believers/atheists/agnostics, the more progressive view of LGBT issues. But I also am a joiner, and believe in creating and belonging to institutions that support my values. There's a real challenge before us in Unitarian Universalism on how to adapt to this new landscape. I'm looking for ideas.