Agnosticism is based on the premise that religious beliefs cannot be professed as true or denied as false unless either claim can be proven. Agnostics participate in several different religions and hold varied beliefs; however, they do not claim to know whether or not any type of deity or deities exist.
Some Agnostics claim simply to not know for themselves whether there is or isn't a god, and some claim that nobody can know whether a deity exists. Those who believe there is a god hold to the claim that they cannot know for sure that god exists because it cannot be proven. Others believe there is no god and lean toward atheism. However, because they cannot prove God doesn't exist they do not claim their belief as truth.
The unity of the Agnostic religion hinges solely on its core premise that one cannot know if a deity exists. Agnosticism has no organized holidays or traditions. Many agnostics celebrate holidays according to their own cultures, family traditions and associated religious beliefs. Agnostics have no set rules for living and do not meet in an organized group like many other religions. Some prefer to hold their beliefs private, while others seek out community in religious or atheistic circles for fellowship.