Painting for Blair's The Grave Friendship
"within those limits we possess each friend not less, but more as the number of those with whom we share him increases. In this, Friendship exhibits a glorious "nearness by resemblance" to Heaven itself where the very multitude of the blessed (which no man can number) increases the fruition which each has of God. For every soul, seeing Him in her own way, doubtless communicates that unique vision to all the rest. That, says an old author, is why the Seraphim in Isaiah's vision are crying "Holy, Holy, Holy" to one another (Isaiah vi,3). The more we thus share the Heavenly Bread between us, the more we shall all have."
The brotherhood of which Blake speaks is not the kinship of being born to the same earthly parents but of recognizing one's kinship to the heavenly family. When we join one another in brotherhood we relinquish some of our self-interest and elevate the interests of others. We affirm the 'brother and friend' within our bosoms and perceive our Souls mingling in the joy of community.
Songs of Innocence & of Experience, (E 28) SONGS 50 A Little BOY Lost "Nought loves another as itself Nor venerates another so. Nor is it possible to Thought A greater than itself to know: And Father, how can I love you, Or any of my brothers more? I love you like the little bird That picks up crumbs around the door." Jerusalem, Plate 88, (E 246) "For Man cannot unite with Man but by their Emanations Which stand both Male & Female at the Gates of each Humanity How then can I ever again be united as Man with Man While thou my Emanation refusest my Fibres of dominion. When Souls mingle & join thro all the Fibres of Brotherhood Can there be any secret joy on Earth greater than this Jerusalem, Plate 4, (E 146) "I am not a God afar off, I am a brother and friend; Within your bosoms I reside, and you reside in me: Lo! we are One; forgiving all Evil; Not seeking recompense! Ye are my members O ye sleepers of Beulah, land of shades!" Letters, (E 705) "Thirteen years ago. I lost a brother & with his spirit I converse daily & hourly in the Spirit. & See him in my remembrance in the regions of my Imagination. I hear his advice & even now write from his Dictate--Forgive me for expressing to you my Enthusiasm which I wish all to partake of Since it is to me a Source of Immortal Joy even in this world by it I am the companion of Angels"
Jesus in John 17 prays that the unity which results form dwelling in the Father and knowing that spirit of God within may be revealed to his readers.
 That they all may be one; as thou, Father, art in me, and I in thee, that they also may be one in us: that the world may believe that thou hast sent me.
 And the glory which thou gavest me I have given them; that they may be one, even as we are one: