nonbelief

noun
non·​be·​lief | \ ˌnän-bə-ˈlēf How to pronounce nonbelief (audio) \

Definition of nonbelief

: absence or lack of belief especially : absence or lack of religious belief nonbelief in God We turn to Dawkins not for his views on sundry social topics, but for clarity on religion and nonbelief. — Jeffrey Tayler