The Syntheist vocabulary constantly returns to the the three terms Atheism, Pantheism, and Syntheism. Atheism is the belief that there has been no god presented to us so far which we can credibly believe in. Atheism is the opposite of theism, the belief that at least one god exists independently of human existence (often divided between monotheism claiming there is one god only as opposed to polytheism believing there are many gods).
Pantheism is the belief that all dualistic theisms are based on mistaken assumptions, that there is no point in discussing God as something external to our obvious existence. According to Pantheism, The Universe and God amount to one and the same thing. God is internal and not external to The Universe and everything that exists is divine. An atheist can therefore also be a pantheist and vice versa. The world’s possibly most ardent atheistic campaigner Rickard Dawkins has even admitted exactly this with his famous quote Pantheism is sexed-up atheism. 
What Syntheism adds to this spectrum is the concept that rather than discussing whether gods exist independently of us or not (as if this for some strange reason would be a necessary condition for divinity), we have to admit that all gods have been created by humanity and nobody else, and we are consequently free to keep creating gods (even physically) as long as we admit that this is precisely what we do when we conduct religion.
So while Atheism and Pantheism are perfectly acceptable passive intellectual positions that amount to pretty much the same thing, two sides of the same coin, it is when we take these concepts seriously and put them in contact with our human emotional needs that we become active Syntheists. Syntheism can best described as Atheism+ or Pantheism+. And no god is more Syntheistic, no god can more lay claim to the term Syntheos, than the sacredness which appears to us when we are bound together (re-ligare) as a holy community.
In other words, Syntheism is religion for the sake of religion alone, without us waiting for any external force to communicate to and dominate us. Instead we become Syntheists through divine communication in between us. The Syntheist symbol shows this interplay: The white ellipse represents The Universe (Pantheos), the black circle represents The Void (Atheos) and the symbol in its entirety represents Syntheos, the sacred unity which we as humans project onto Existence.
Syntheology is even based on four rather than three basic concepts, but the forth one, the sophisticated and mysterious concept of Entheos, “The God inside you”, does not seem to require its own -ism, which is why we happily study this concept deeper in a different article.
 Richard Dawkins, The God Delusion, page 40. “Deists differ from pantheists in that the deist God is some kind of cosmic intelligence, rather than the pantheist’s metaphoric or poetic synonym for the laws of the universe. Pantheism is sexed-up atheism”.