In his first letter to Samuel Clarke, which initiated their famous correspondence, Gottfried Leibniz writes, “Natural Religion it self, seems to decay [in England] very much. Many will have Human Souls to be material: Others make God himself a corporeal Being.” The subsequent exchange concerning metaphysics between the two men was published in English in 1717. Although he wrote these letters over 70 years before Blake composed his tractate, There is No Natural Religion (1788), Leibniz here anticipates—and bemoans—Blake's argument against natural religion and, particularly, his ultimate claim that “God becomes as we are [Leibniz's ‘corporeal Being’], that we may be as he is.” Whatever decay of natural religion that Leibniz perceived in the early eighteenth century had not been completed by Blake's time, since the latter's title is a contentious assertion against majority belief, rather than a pronouncement of a state of affairs (“natural religion is no more”). Well over 100 works featuring “natural religion” in their title were published in the eighteenth century, not to mention the hundreds more that address the synonymous term, deism, in their titles and contents, and Leibniz's correspondent is a prominent example of the topic's popularity: Clarke's Discourse Concerning the Being and Attributes of God, the Obligations of Natural Religion, and the Truth and Certainty of the Christian Revelation went through 13 editions between 1705 and 1767, and his Discourse Concerning the Unchangeable Obligations of Natural Religion, and the Truth and Certainty of the Christian Revelation went through 5.

Natural religion's connotations evolved over the course of the eighteenth century, but certain core principles remained, namely: God is a transcendent being, an infinite first cause separate from and superior to the material universe he set in motion; and, as George Cheyne, the physician to Alexander Pope and Samuel Richardson, wrote in 1705, the material universe is inanimate: “[t] hat active principle which animates […] the dead mass of bodies, and which is the cause of all the beautiful appearances of nature, owes its origin to something different from matter and motion, and therefore this system of things could not arise from thence.”