Among Blake's Prophetic Books, Milton stands out as both the most personal and also the one which is most concerned with the role and function of the poet. The framework of it, as one might expect, is Blake's complex engagement with Milton, and it differs sharply from the alternative engagement offered in The Marriage of Heaven and Hell. In Milton, Milton is shown initially as a figure of error who, in Paradise Lost, misrepresented God. Behind this lies Blake's own oft-repeated conviction that there is no God at all if one considers Him to be distinct from man; on the contrary, God resides only in the human breast. Milton, on the other hand, had shown God as an external, authoritarian figure.
Punter, David. "Milton". The Literary Encyclopedia. First published 24 January 2002
[https://www.litencyc.com/php/sworks.php?rec=true&UID=3581, accessed 22 March 2018.]