PAUL PREACHING

Following his experience at the Truchsessian Gallery when the light which he had enjoyed in his youth returned to him, Blake began to express the new-found appreciation that the depiction of light might play in his painting. Blake felt that he was returning to a style in which he had originally painted and which reflected the "true light that enlightens every man."
 
Blake's St Paul Preaching at Athens, one of the Biblical watercolors for Thomas Butts executed in 1803, is an example of the simplicity, directness and transparent symbolism which characterize his re-enlightened approach. 
 
Notice the light that surrounds St Paul, the presence of multiple generation is his audience, and the reactions displayed by various characters. In Blake's picture St Paul looks out at  the audience whom he wishes to address not at those gathered around him. The unadorned simplicity of the picture is congruent with the same quality in Luke's account in Acts.
 
Acts 17
[14] Then the brethren immediately sent Paul off on his way to the sea, but Silas and Timothy remained there.
[15] Those who conducted Paul brought him as far as Athens; and receiving a command for Silas and Timothy to come to him as soon as possible, they departed.
[16] Now while Paul was waiting for them at Athens, his spirit was provoked within him as he saw that the city was full of idols.
[17] So he argued in the synagogue with the Jews and the devout persons, and in the market place every day with those who chanced to be there.
[18] Some also of the Epicurean and Stoic philosophers met him. And some said, "What would this babbler say?" Others said, "He seems to be a preacher of foreign divinities" -- because he preached Jesus and the resurrection.
[19] And they took hold of him and brought him to the Are-op'agus, saying, "May we know what this new teaching is which you present?
[20] For you bring some strange things to our ears; we wish to know therefore what these things mean."
[21] Now all the Athenians and the foreigners who lived there spent their time in nothing except telling or hearing something new.
[22] So Paul, standing in the middle of the Are-op'agus, said: "Men of Athens, I perceive that in every way you are very religious.
[23] For as I passed along, and observed the objects of your worship, I found also an altar with this inscription, `To an unknown god.' What therefore you worship as unknown, this I proclaim to you.
[24] The God who made the world and everything in it, being Lord of heaven and earth, does not live in shrines made by man,
[25] nor is he served by human hands, as though he needed anything, since he himself gives to all men life and breath and everything.
[26] And he made from one every nation of men to live on all the face of the earth, having determined allotted periods and the boundaries of their habitation,
[27] that they should seek God, in the hope that they might feel after him and find him. Yet he is not far from each one of us,
[28] for `In him we live and move and have our being';
as even some of your poets have said, `For we are indeed his offspring.'
[29] Being then God's offspring, we ought not to think that the Deity is like gold, or silver, or stone, a representation by the art and imagination of man.
[30] The times of ignorance God overlooked, but now he commands all men everywhere to repent,
[31] because he has fixed a day on which he will judge the world in righteousness by a man whom he has appointed, and of this he has given assurance to all men by raising him from the dead."
[32] Now when they heard of the resurrection of the dead, some mocked; but others said, "We will hear you again about this."
[33] So Paul went out from among them.
[34] But some men joined him and believed, among them Dionys'ius the Are-op'agite and a woman named Dam'aris and others with them.

Letters, To Thomas Butts, (E 723)
"Patience! if Great things do not turn out it is because
such things depend [xxxx] on the Spiritual & not on the
Natural World & if it was fit for me I doubt not that I should be
Employd in Greater things & when it is proper my Talents shall be
properly exercised in Public. as I hope they are now in private.
for till then.  I leave no stone unturnd & no path unexplord that
tends to improvement in my beloved Arts.  One thing of real
consequence I have accomplishd by coming into the country. which
is to me consolation enough, namely.  I have recollected all my
scatterd thoughts on Art & resumed my primitive & original ways
of Execution in both painting & Engraving. which in the confusion
of London I had very much lost & obliterated from my mind.  But
whatever becomes of my labours I would rather that they should be
preservd in your Green House (not as you mistakenly call it dung
hill). than in the cold
gallery of fashion.--The Sun may yet shine & then they will be
brought into open air."

 Blake was familiar with this picture by Raphael of St Paul Preaching in Athens. His admiration for Raphael notwithstanding, he followed his own leading whatever the consequence.