Here are the last fourteen lines of William Blake’s “The Everlasting Gospel”:
The Vision of Christ that thou dost see
Is my Vision’s Greatest Enemy.
Thine has a great hook nose like thine;
Mine has a snub nose like to mine.
Thine is the friend of All Mankind;
Mine speaks in parables to the Blind.
Thine loves the same world that mine hates;
Thy Heaven doors are my Hell Gates.
Socrates taught what Melitus
Loathd as a Nation’s bitterest Curse;
And Caiphas was in his own Mind
A benefactor to Mankind.
Both read the Bible day & night,
But thou readst black where I read white.
Often, when you see this passage of Blake’s quoted, the last six lines are cut off, and we get only the first eight, which are perhaps a bit more obviously lyrical, and are readily comprehended.
But if we read these fourteen lines of Blake’s as a pseudo-sonnet, then we recognize that the last six lines really cannot be lopped off from the first eight without damage to the author’s didactic intent, for they constitute an important shift in the poem.
What the first eight lines portray as almost comic differences of perception concerning Jesus, the last six lines show as not funny at all, but turning murderous. Freud’s “narcissism of small differences” becomes, in Blake, the pretext for persecutions, trials, gross injustice, and deadly violence.
The trials of Socrates and Jesus are Blake’s exhibits A and B.
Miletus, one of the “prosecuting attorneys,” or accusers, at Socrates’s trial, asserted that Socrates, by teaching his peculiar brand of reasoning to the young, corrupted the youth, and so should be forced into silence.
In turn, Caiphas, the interrogating high priest before whom Jesus appears in the gospels, believed that he was protecting normative Judaism against a sectarian fanatic.
Blake depicts both persecutors as pious men, reading “the Bible day & night.” (Of course, Miletus’s “Bible” would have been Homer and not the Hebrew prophets, and Homer was indeed quoted, and appealed to, in ancient Greece, to settle pagan sectarian disputes. Homer, for example, was used both to defend Socrates as well as attack him.)
As is characteristic of Blake’s poetry elsewhere, if we hold all fourteen lines together, and do not separate them, we get a discomfitting movement from innocence to experience.
In this case, Blake’s lines move from a sophomoric argumentative innocence about the Bible, to a more sobering adult experience, in which intense biblical study leads some to the conclusion that they must, in the name of a higher good, annhilate those who they perceive are the Bible’s enemies.
Prometheus Unbound 
Your–enjoyable and thought-provoking–post begs the question, what is “everlasting” about this particular gospel?
Blake, being an inveterate and explicit “contrarian,” placed a great deal of value in the power of dialectical oppositions. This is what he admires in the Jesus of the NT and it is also what he admires in the Socrates of the dialogues.
Your post uses the term “diadactic”; this can be applicable only in the most gnomic and ironic of ways. Blake’s didacticism is a teaching or preaching that seeks only to cancel out entrenched dogma and ossified intellectual positions (or emotional reaction formations masquerading as same). The phrase that best applies here is “melting apparent surfaces away” (from The Marriage of Heaven and Hell). Blake’s dialectic is a corrosive to dogma, and the one consistent dogmatic sentiment that he iterates and reiterates is “There Is No Natural Relgion”–simultaneous with “All Religions Are One.” This sincere play, this reverential mockery of all things revered, is pervasive in Blake. The one constant is his opposition of anti-systemic systematizing vs. the dominant ideologies of his time: “I must create a system, or be enslaved by another man’s,” as he famously declares in Jerusalem, fully aware of the irony of this stance. But the rest of the utterance supplies the backbone of his irony: “I will not reason and compare. My business is to create.”
Well, so is the business of all of us–affirmative creation. “A Poet, a Painter, a Musician, an Architect: the man or woman who is not one of these is not a Christian.” But how do we create? We do it by active, dialectical opposition with the ideologies that surround us: “The vision of Christ that thou dost see, is my vision’s greatest enemy.” We cannot parasitically infest–or feed from–another’s spiritual vision. We must be accountable for our own, recreating it moment by moment in an act of affirming will. Note that this does not mean cancelling out or “negating” the Other’s vision. Oh, no. It means merely resisting its alluring “mild blandishments.”
Not many folks have the stamina for this sort of thing. It is at once exhausting and energizing. It sustained Blake for seventy of the toughest years that any mere human has ever persevered through. So that’s a recommendation of sorts, I suppose.
[BTW–Blake was never a lover of the sonnet form. One sees this as early as the Poetical Sketches. Rather, he was a devoted adherent of the English ballad tradition (“English Blake” vs. the decadence of various contintental traditions), and his verses almost always reflect that alignment. Were he to have composed a sonnet proper, as a derivative of the Italian literary and folk tradition much alloyed with the iconography and ideation of the Papist church, it likely would have been in the manner of a parody. (Here I use “Papist” advisedly, as the sort of bigoted negation routinely posted as sentinel dragons obstructing the gate to human progress.)]
not that it matters,
your point on blake and sonnet form is interesting—i’ll have to think about that.
as for your observation that blake does not mean to cancel or negate others’ visions, i’m less certain about your perspective there.
i think that blake is certainly capable of being didactic.
blake, for example, seems to see the ENLIGHTENMENT as a kind of impoverishment of the human imagination, and he doesn’t seek (in my reading of him) a truce or compromise with it, or even an integration of it into a higher scheme (except as something to gain energy from through resistence).
and i think, for example, that Melitus and Caiphas (in the above poem) are, in blake’s scheme, URIZEN figures engaging in negation through oppression, and that socrates and jesus are poetic LOS figures.
i think that you are right that the “everlasting gospel” is the creative imagination, but i’m not sure that blake thought he could make absolutely everything fit harmoniously into it.
i not sure, in other words, if i can read blake as if he is a poetic version of hegel or liebnitz, forcing all of existence into a higher unity and destiny.
but you might be right about this. i’ll have to think about it.
as someone who is not a fan or hegel or liebnitz, it’s disturbing to think of blake in this way.
i’d like to think of blake as being on the side of the little guy.
not that it matters wrote:
Blake’s didacticism is a teaching or preaching that seeks only to cancel out entrenched dogma and ossified intellectual positions (or emotional reaction formations masquerading as same). The phrase that best applies here is “melting apparent surfaces away” (from The Marriage of Heaven and Hell). Blake’s dialectic is a corrosive to dogma, and the one consistent dogmatic sentiment that he iterates and reiterates is “There Is No Natural Relgion”–simultaneous with “All Religions Are One.”
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So, how is that NOT didactic? For someone so erudite you seem to have a poor grasp on that word’s meaning. If anything, you have only strengthened the case for didacticism with this line of argument.
At the very least, other poets can certainly take instruction from Blake’s ‘corrosive dialectic’. In brief, just because something is irreverent or ironic does not preclude it from being didactic.