The phrase "five smooth stones" comes from the Biblical account of David and Goliath. Those rocks were all the puny shepherd had at hand when faced with a seemingly unbeatable foe. However, I first heard this phrase in a pamphlet I picked up somewhere in Cambridge, Massachusetts. Titled "The Five Smooth Stones of Religious Liberalism," it's a collection of excerpts from James Luther Adams' book On Being Human Religiously.
Adams was one of the chief American theologians of the modern Unitarian Universalist movement. I don't know much about where the UU's fit into the larger tapestry of religion and/or New Age spirituality, but I've always kind of liked them.
Adams' Five Smooth Stones encapsulate a mini-manifesto of his conception of UU belief and practice. Unfortunately, Adams never boiled them down into a short list like many of the others that I've highlighted so far. Each "stone" in Adams' book was a full essay. Even that little pamphlet that I picked up 20 years ago contains 13 or 14 pages of dense, unillustrated text. :-) If you search, you'll find some pithy encapsulations, but none that are authoritative. Here's my own attempt to boil them down to a blog post.....
1. Revelation is continuous. The Divine speaks to us in our time, just as in all previous times. Because revelation is still not complete, "nothing is exempt from criticism."
2. Freedom of association. This applies not only to person-to-person relationships (no coercion or slavery), but also to the relationship between pulpit and pew. The whole reward & punishment scheme that some religions invoke is off the table. Love, especially, can only be good and true when it's given freely. It's all about trust.
3. A just & loving community. All this talk about love and freedom is worthless without application to the real world. It's difficult, though, since building a fair, equitable community sometimes means balancing freedom against responsibility. Adams waxes very Biblical when talking about this; balancing the Old Testament prophets against Jesus' humble mustard seed.
4. Do good to be good. In some theologies, virtue is elevated to being an abstract, absolute entity. Not for Adams. Goodness only exists when it's exercised and put into practice. There's that real world again. Do you really believe what you say you believe? Put your money where your mouth is, mister.
5. Ultimate Optimism. The universe may not provide everything we want or need, but it provides enough for us to do good, meaningful work in life. The worst roadblocks are internal, and we can overcome them. At least we have hope.