"you are not of this world" (John 15:19)
The committed Christian may eventually come to realize that; secular people may be oblivious to it. . Most of us jump back and forth between the Kingdom of this World, (which Blake called the Sea of Time and Space) and the Kingdom of God; a handful of spiritual geniuses may see in it their own nature. Such a person was our poet.
Blake has often been called the First Romantic. In Blake's day the word romantic denoted a train of thought outside of what the materialists of the Enlightenment allowed themselves for general discourse; religion was supposed to be private and in positivistic terms meaningless.
But Blake was different: religion (in the fullest sense) was all that mattered to him-- yes, we have to live in the world, but the less we do it the better we are (in Blake that meant in order to put bread on the table).
Here's a morsel from the Vision of the Last Judgment:
"I assert for My self that I do not behold the Outward Creation & that to me it is hindrance & not Action it is as the Dirt upon my feet No part of Me. What it will be Questiond When the Sun rises do you not see a round disk of fire somewhat like a Guinea O no no I see an Innumerable company of the Heavenly host crying Holy Holy Holy is the Lord God Almighty" (Erdman 565)
The Hound of Heaven powerfully portrayed the two kingdoms. The early Blake portrayed the same thing in a contrary way: his (negative) Spectre was just as persistent as Thompson's (positive) hound. Most people carefully hide those ideas from consciousness; for Blake they were a conscious and continuous reality-- "round me night and day".
In Blake's poetry The two kingdom's were first expressed in The Marriage of Heaven and Hell. In his contrary way Blake considered angels to be those most conformed to the world, and devils to be those free from it. (Read it again in that light!)
Announcing that position Blake found himself to a very great degree persona non grata; only a handful of people had any sympathy for his point of view. He proposed a new Way, and his life in many ways resembled that of Paul , uniformly ignored by the intellectual public whom he tried to reach.
For half of Blake's life he had focused on the Spectre, but the true 'hound' came with his meeting with Jesus at the Moment of Truth.
In the Sea of Time and Space various Blake interpreters identify the man on the shore with Apollo or Odysseus; Damon identified him as the red robed Luvah. (The Four Zoas [Nt 1], 13.9; E308. All of these are meaningful.)
What do you make of "one like the Son of God" in the furnace? How about the red robed Luvah in the furnace? Blake had a lot to say about furnaces, but it wasn't until he reached spiritual maturity that he understood who was in the furnace.
"he came into the world", and the world did to him what it would. In Jerusalem Blake identified the redeemed Luvah as Jesus- in contrast to the satanic Urizen.