Because Blake's later poetry contains a private mythology with complex symbolism, his late work has been less published than his earlier more accessible work. The Vintage anthology of Blake edited by Patti Smith focuses heavily on the earlier work, as do many critical studies such as William Blake by D. G. Gillham.
The earlier work is primarily rebellious in character and can be seen as a protest against dogmatic religion especially notable in The Marriage of Heaven and Hell, in which the figure represented by the "Devil" is virtually a hero rebelling against an imposter authoritarian deity. In later works, such as Milton and Jerusalem, Blake carves a distinctive vision of a humanity redeemed by self-sacrifice and forgiveness, while retaining his earlier negative attitude towards what he felt was the rigid and morbid authoritarianism of traditional religion. Not all readers of Blake agree upon how much continuity exists between Blake's earlier and later works.
Psychoanalyst June Singer has written that Blake's late work displayed a development of the ideas first introduced in his earlier works, namely, the humanitarian goal of achieving personal wholeness of body and spirit. The final section of the expanded edition of her Blake study The Unholy Bible suggests the later works are the "Bible of Hell" promised in The Marriage of Heaven and Hell. Regarding Blake's final poem "Jerusalem", she writes: "[T]he promise of the divine in man, made in The Marriage of Heaven and Hell, is at last fulfilled."
John Middleton Murry notes discontinuity between Marriage and the late works, in that while the early Blake focused on a "sheer negative opposition between Energy and Reason", the later Blake emphasised the notions of self-sacrifice and forgiveness as the road to interior wholeness. This renunciation of the sharper dualism of Marriage of Heaven and Hell is evidenced in particular by the humanisation of the character of Urizen in the later works. Murry characterises the later Blake as having found "mutual understanding" and "mutual forgiveness".