"That of God in everyone" virtually defines Quakerism to many (especially East Coast) Quakers. So look at Blake's A Divine Image:
"Songs of Innocence 1789
"To Mercy Pity Peace and Love.
All pray in their distress:
And to these virtues of delight
Return their thankfulness.
For Mercy Pity Peace and Love,
Is God our Father dear:
And Mercy Pity Peace and Love,
Is Man his child and care.
For Mercy has a human heart
Pity, a human face:
And Love, the human form divine,
And Peace, the human dress.
Then every man of every clime,
That prays in his distress,
Prays to the human form divine
Love Mercy Pity Peace,
And all must love the human form.
In heathen, Turk or jew,
Where Mercy, Love and Pity dwell,
There God is dwelling too." (Erdman 32)
You can hardly read that poem without awareness of Blake's inveterate Universalism, also shared by most Quakers interested in Christian theology. Look especially at the last verse and translate into prose: God is dwelling in heathens, Turks (muslims) and Jews.
Or perhaps God is dwelling in heathens, like Muslims and Jews.
(This like everything else Blake wrote is subject to many interpretations; in fact that's the real meaning of the word poetry.)
When I started reading Blake, I looked and looked for some mention of Quakers because his values in general seemed remarkably similar to Quaker values. But it was in vain. I wondered why; then I realized that it was most likely because of his keen awareness that Quakers were in the forefront of the Industrial Revolution.
The Industrial Revolution was anathema to Blake; he spoke of the satanic mills:
("And was Jerusalem built here
Among these dark Satanic Mills?")
(from the preface to Milton; Erdman 95)
Another pointer is found in London where he spoke of the mind forg'd manacles; here I think he meant the systematic propaganda that
lulled the Enlish peasants (and most of us today) into a comfortable acceptance of our actual slavish lot in life.
The Industrial Revolution and globalization as well have enormously enriched the already wealthy and impoverished the poorest among us. In the long run most of us see a positive (for example 300 million Chinese peasants are said to have escaped poverty; while a few million Americans lost their jobs).
But for Blake it was a feeling thing, and he had very powerful feelings about all the poor wretches who crowded the streets of London after being disinherited from their land rights throughout England.
Aside from the matter of the Industrial Revolution the values that Blake and Quakers had in common are numerous:
George Fox believed deeply in removing the occasion of War; Blake hated war.
Quakers have always despised the slave trade; so did Blake.
There are many others; they may lead to other posts.