Claim. God is the vertical true parent; humans are born connected to vertical love alone unless horizontal True Parents are also established, so the couple in the position of physical true parents is structurally necessary for the providence.
Elaboration. “God is the vertical parent who has true love for humankind … The vertical Father requires a horizontal father that can unite with Him … He is needed to create a sphere. A being cannot just form a sphere on its own” (3.1. True parents, true couples, and true children, 182-143, 1988.10.16). The pairing is anti-Gnostic: “If God were the owner of the vertical love only, the children conceived by Him would maintain just a single vertical line. He would not be able to have them expand horizontally. On account of this, He is not the one who would give birth to His children. Instead, He would have them born through true parents” (ibid, 182-258, 1988.10.23). Sexual reproduction is folded in: “Reproduction takes place on earth … Babies cannot be born in the spirit world” (ibid, 213-265, 1991.1.21). The implication: incarnational lineage is not optional add-on but the geometric condition for love’s sphere — vertical alone cannot make a Kingdom.