The Necessity of Atheism was first published by Shelley in 1811. In 1813 he printed a revised and expanded version of it as one of the notes to his poem Queen Mab.
Shelley evinced a searing contempt for organized religion but maintained a belief in a benevolent non-sectarian World Spirit.
in the opening statement of this pamphlet, he makes clear the nature of his qualified deism :
"There is no God. This negation must be understood solely to affect a creative Deity. The hypothesis of a pervading Spirit co-eternal with the universe remains unshaken."