The shading here seems deliberately suggestive of Milton's Satan. From the very first, the Satanic legions sense that the fall from heaven has diminished their spiritual essence, and, as in these early words of Satan's chief follower Beelzebub, that loss is expressed in terms of "glory."
the mind and spirit remainsThe most resonant identification of diminished glory with the fall of the angels is uttered by Satan as he soliloquizes atop Mount Niphates at the opening of Book IV. There, as he addresses the Sun, the fallen archangel directly contrasts himself and God in terms of their manifestation of glory.
Invincible, and vigour soon returns,
Though all our glory extinct, and happy state
Here swallowed up in endless misery. (I.139-42)
O thou, that, with surpassing glory crowned,
Lookest from thy sole dominion like the God
Of this new world; at whose sight all the stars
Hide their diminished heads; to thee I call,
But with no friendly voice, and add thy name,
O Sun! to tell thee how I hate thy beams,
That bring to my remembrance from what state
I fell, how glorious once above thy sphere;
Till pride and worse ambition threw me down
Warring in Heaven against Heaven's matchless King. (IV.32-41)