In recent years it has been learned that William Blake's mother had been a Moravian during her first marriage and was said to have been from a Moravian family. After her husband's death she left the Moravians and married James Blake in 1752.
The Moravians originated in central Europe and moved about as they were persecuted for their non orthodox beliefs and practices. They emphasized a religion of the heart, expressed in a life of religious disciplines and freedom for emotional and aesthetic activities.
They had a missionary zeal to spread the Gospel and sent members to far flung sites. Peter Bohler was sent to England to establish contact with Christians at Oxford. He became associated with a young John Wesley and they both traveled to the new colony in Georgia which had been established to provide opportunity for the British underclass such as those in the debtor's prison - the Marshalsea.
When Wesley and Bohler returned to London they were among those who established the Fetter Lane Society in 1738. As were many religious societies in that day, Fetter Lane was non denominational. Later Wesley left Fetter Lane and established Foundry and other societies which became the foundation of the Methodist Church. Fetter Lane became the Moravian Church to which Catherine Armitage applied for membership in 1750. During the period when Blake was a young man, Wesley was active in his ministry throughout England: preaching salvation from sin, organizing societies for the converted to grow in the faith, encouraging a deep personal religious experience among believers.
Wesley, the Oxford educated son of a Church of England minister preached in the fields to the outcasts, the poor and oppressed, and converted them to lives of sobriety and frugality. Blake, the son of a hosier, without formal education created sublime poetry and artwork to speak to the intellect and imagination about the possibility of living in Eternity. Both men were unaccepted by the establishment. Both men carved out distinctive lifestyles to carry out their religious vision. Both were significantly influenced by the Moravian movement which found form in a little meeting called the Fetter Lane Society.
Wesley had nothing to say about Blake, but Blake made mention of Wesley with admiration.
Milton, Plate 22, (E 117)
"O Swedenborg! strongest of men, the Samson shorn by the Churches!
Shewing the Transgresors in Hell, the proud Warriors in Heaven:
Heaven as a Punisher & Hell as One under Punishment:
With Laws from Plato & his Greeks to renew the Trojan Gods,
In Albion; & to deny the value of the Saviours blood.
But then I rais'd up Whitefield, Palamabron raisd up Westley,
And these are the cries of the Churches before the two
Faith in God the dear Saviour who took on the likeness of men:
Becoming obedient to death, even the death of the Cross
The Witnesses lie dead in the Street of the Great City
No Faith is in all the Earth: the Book of God is trodden under Foot:
He sent his two Servants Whitefield & Westley; were they Prophets
Or were they Idiots or Madmen? shew us Miracles!
PLATE 23 
Can you have greater Miracles than these? Men who devote
Their lifes whole comfort to intire scorn & injury & death"