The may be similar to the thread about what paganism is, but I suppose there is a slight semantic difference.
Like many here, I think a reverance for nature may be a common factor, but generally, I just imagined the world that did not fit into an agnostic nor an atheist worldview. I believe things to be more connected than that, and it's very hard to describe without using such worn out words as energy or force. I have simply chosen to view our universe and how it maintains itself as an energy flow, it goes round and round. I should add, I am a follower of the Big Bounce, so I suppose the idea of something being cyclical is quite important to me.
For a long time I could not fully describe what I meant with energy or force either, until I dug up a bit about Einstein's relativity theory that equals mass to energy. The problem is that when I say, see a flower, I just don't see the flower as a physical object, I also see it as a part of a greater whole where the flower at some point will die, decompose and be meaningful to other lifeforms.
It can however be more properly and throughly explained once Einstein's theory is applied I think, and in a way it is pantheistic/taoistic, which is why I always found it so hard to settle with what to call myself. When I mean pantheistic also, I don't mean it with its original connotations of there being a sentient being, but more something to Spinoza's god, something Einstein also believed in and I think that just makes so much sense.