One of the most entertaining pieces ever written about theism is H.L. Mencken's very brief Memorial Service, in which he sardonically wondered where the "grave-yard of dead gods" can be found before proceeding to list dozens of gods that people used to, but no longer believe in. Some are recognizable, others are not. "They were gods of the highest standing and dignity -- gods of civilized peoples -- worshiped and believed in by millions," Mencken wrote. "All were theoretically omnipotent, omniscient, and immortal. And all are dead."
It's easy to forget the myriad of gods and religions that have been relegated to the dustbin of history, especially when monotheism has prevailed in most of the world for some time now. Regardless, all religions are inherently presumptuous in the sense that they each purport to be the one true religion. But on a planet that has seen thousands of religions come and go, it's hard to make the case that any one faith has more claim to legitimacy than another. The evolution of religion throughout the millennia makes for a fascinating study, and one that is colorfully told in this chart:
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Compiled by Simon E. Davies, who runs The Human Odyssey Facebook page, the graphic charts the origins of contemporary religious beliefs going back 100,000 years. Davies himself issues the caveat that "due to the vague nature of mythology [and the lack of adequate written records from thousands of years ago] the origins of many of these faiths are estimates only." However, uncertainty of origins aside, the chart's mapping of the more recent schisms and offshoots make for an accurate and vivid visual aid in understanding the historical relation these religions have to one another, even if you have no idea what some of these religions are. Atenism, anyone?
Davies' chart shows only the better-known religions because there is simply not enough room to include every minor faith that is known to exist or to have once existed. Even still, the sheer number of faiths displayed here should serve as a helpful reminder that the mere act of adhering to a particular faith is a show of arrogance: Everyone who doesn't believe what I believe is wrong.
There have been thousands of religions throughout history, but that's hardly need for concern since, yours is probably the right one.