The basic fact that Odin is a fucking bad ass and you totally want him to be your God. The dude has one eye, was impailed by his spear for 9 days, and he has fucking ravens as pets...seriously? How much more bad ass can you get? The religion is based off the sole fact of screaming loudly and epically into the sky (while shaking your fists) to Odin for whatever you want. (Usually weather realated.)
Example of Odinism at work:
Greg: "Dude, Odin isn't real."
Jordan: "Oh yeah? (While shaking fists to sky) ODIN BRING FORTH A RAIN STORM!"
*later that day at a football game*
Greg: "Holy shit it's fucking raining like crazy!"
Jordan: "Damn straight."
The worship of the Norse God Odin; someone who is primarily dedicated to Odin. Can sometimes, but not always, be used interchangeably with Asatru and Heathen. Odinism is a polytheistic religion; even though the focus is often on Odin, other of the Aesir and Vanir are somerimes worshiped as well. It is not a Neo-Pagan or New Age religion. Odinism is an ancient indigenous religion of Northern Europe that predates more well known religions as Hinduism, Buddhism, Judaism; and Islam and Christianity who are but mere babies in contrast.
There are Asatruar and Odinists who feel that they are the same religion, while many others who feel that Asatru and Odinism have distinct differences.