Claim. God assigned Lucifer to the position of archangel and made him the channel of God’s love to the angelic world. After God created humans and loved them more than His servant Lucifer, Lucifer felt a relative decrease in love — and this perceived loss was the motivation of the fall.
Elaboration. Per 2.2.1. The Spiritual Fall: “God created the angelic world and assigned Lucifer to the position of archangel. Lucifer was the channel of God’s love to the angelic world, just as abraham was the channel of God’s blessing to the Israelites. In this position he virtually monopolized the love of God.”
The mechanism is relative-comparison, not absolute-deprivation: “God’s love toward Lucifer did not change; it was the same before and after the creation of human beings. Yet when Lucifer saw that God loved Adam and Eve more than him, he felt as if there had been a decrease in the love he received from God.”
DP analogizes the laborers-in-the-vineyard parable (Matt 20): the morning-shift laborers were paid fairly but felt underpaid when later-shift workers received the same. “Lucifer, feeling as though he were receiving less love than he deserved, wanted to grasp the same central position in human society as he enjoyed in the angelic world.” This was why he seduced Eve.
This atomic names Lucifer specifically (not generic-angel) as the archangel. DP treats this naming as straightforward; orthodox biblical scholarship contests the Isa 14 / Ezek 28 → Satan equation. Parking-thread anchor for that contested identification.
See also. dp-serpent-is-the-fallen-archangel, dp-four-primary-fallen-nature-characteristics