At some point in modern times (and yes, I suspect the ever suspect Sixties), Americans started losing their grip on the masculine, white-bearded, sometimes nice, sometimes nasty God of old-time religion, and started entertaining other cosmic possibilities.

An early signal of this sea change was philosopher Jacob Needleman’s classic 1970 book, The New Religions, that first suggested that the Judeo-Christian establishment was beginning to face some upstart competitors.

Then in 1988, a little-noticed, but hugely significant poll was conducted by Better Homes and Gardens magazine on “Religion, Spirituality, and the American Family.” Hugely significant because BH&G was decidedly not a voice of the counterculture, but even more so because its survey drew a whopping 80,000 responses (far outstripping most public opinion polls) and came up with these findings:

“Some results suggest that respondents’ spirituality is strongest on a personal level. The largest group (62%) say that in recent years they have begun or intensified personal spiritual study and activities (compared to 23% who say they have become closer to a religious organization). 68% say that when faced with a spiritual dilemma, prayer/meditation guides them most (compared to 14% who say the clergy guides them most during such times)….”

Flash forward to 2006, when a Gallup Poll commissioned by the Spiritual Enterprise Institute found that the proportion of Americans claiming to be “spiritual, but not religious” had risen from 30% to 40% just since 1999. These days, of course, “spiritual, but not religious” has become a buzzphrase, having entered the popular parlance on matchmaking sites, gained its own Wikipedia entry, and spawned a website.

But our singular, superannuated Heavenly Patriarch may finally be shown the cosmic door by today’s young folks. In the spring of 2010, a truly startling survey was released by Lifeway Christian Resources, a research and marketing arm of the Southern Baptist Convention (again, not exactly a bunch of zenned-out progressives). Lifeway’s research suggested that 72% of the Millennial generation — people now in their 20’s — identify themselves as “more spiritual than religious.” About a third of this population still attends church — but for how long? As Lifeway President Thom Rainer has said, the continuance of this trend may mean that, “the Millennial generation will see churches closing as quickly as GM dealerships.”

There’s some good news and some vague news in this shift of public sentiment. That is, we all know what “religious” means:

1. believing in God (our particular religion’s God, that is);
2. regularly going to our church, temple, or mosque (or saying we do);
3. tithing (or sending a tear-spattered check to our favorite hortatory televangelist);
4. following (or pretending to follow) the commandments and dictates of our religion;
5. presuming that our religion is better than all those other religions, and so on.

But “spiritual” can mean pretty much anything: from spending years following a focused contemplative discipline, to a few minutes spent trying to sit in full lotus and then deciding that our soul really needs a banana split (just like it did last time). Between the soul-crushing dictates of that old-time religion and the self-indulgent temptations of what is loosely called “spirituality” there lies a huge, ambiguous territory.

For better or worse, it looks like a rapidly increasing crowd of Americans is trekking forth into that territory without that old familiar, monotheistic God at their side (albeit with a whole host of cooler, feminine deities, angel guides, tree spirits, channeled entities, and Big Mind).

Here’s the zinger, though: this spiritual peregrination may not be so much a new-fangled fad as a resumption of the real American religious tradition. Check out Robert C. Fuller’s study Spiritual But Not Religious: Understanding Unchurched America and Mitch Horowitz’s Occult America: White House Seances, Ouija Circles, Masons, and the Secret Mystic History of Our Nation and you’ll get the distinct impression that “going rogue” with your own spirituality is as innately and distinctly American as flipping off the British monarchy. In fact, many of the original settlers in the New World were the religious radicals of their time, and their spiritual legacy is more fairly claimed by the various expressions of “SBNR” than by contemporary mainstream religion.

Like a lot of folks, I’ve ridden all the way around on the religion and spirituality carousel — but I’ll reveal all that in the next edition of Sense & Spirituality: “Sick of Religion, Cured by Spirituality.”