Claim. Human beings were created as the interface between the spiritual and physical worlds; without them, the two worlds cannot communicate or be unified.
Elaboration. SMM gives this as the structural role of humankind in creation: “God made all things and humankind. Everything began with God at the center. Through creating people, He wanted to see Himself in oneness with humankind and all things in a position of equilibrium; such was His will in the creation. There was God and there was the created world, and humankind stood in the middle between them. As such, human beings function as the interface between the spiritual and physical worlds” (2.2. Human beings as the interface between spiritual and physical worlds, 67-143, 1973.6.1). The mind-body composition mirrors this: “we represent all of history and all destinies of the future, and therefore possess cosmic value” (ibid, 4-267, 1958.8.3). The interface is not metaphor — humans physically and spiritually mediate between two real worlds, which is why salvation cannot bypass the body.