Approaching the works of William Blake from many different angles, one encounters the centrality of relationship to God. His poetry, his paintings, his engravings, and other events in his life mirror his strong and independent spirituality. Blake, like most passionate Christians, wasn't very impressed by the church - true faith, he thought, was found in the use of one's mind. Religious institutions, like the church, were at best nice options, at worst, harmfully oppressive systems.
Blake made his bold religious claim that "there is no natural religion," entering an important debate in his era. On the one hand, there were those asserted that there is such a thing as a "natural religion," meaning a significant knowledge of God available through the five physical senses and human reason's ability to process the data yielded by those senses; in this group we would find individuals such as Descartes and Leibniz. On the other hand, there were those who agreed with Blake, positing that instead of "natural religion," humans could have a more accurate form of knowledge in "revealed religion": knowledge of God shown to the human race in the form of inspired texts; in this camp, we find John Locke, Robert Boyle, Michael Faraday, and Isaac Newton.
Blake's careful analysis of religious belief led to his interpretation of the French Revolution as a spiritual event rather than a political or economic event. The shuffling of different governmental forms in Paris was merely the surface: a deeper cosmic struggle was, in Blake's mind, the cause of atrocities and mass executions.
Initially enthusiastic about the overthrow of the absolutist monarchy in France, Blake began a long poem in praise of the revolution. When the "reign of terror" began, however, his hopes soured, and he saw, in part, a noble cause gone bad, led astray by evil influences, and in part a cause which from its very beginnings had a sinister strain hidden beneath its claims to merely seek liberty. Blake saw this, not as a political struggle between social classes, but rather as a struggle between good and evil, between love and selfishness, and between selflessness and sin.