Claim. Earth is the sole production center for the citizens of heaven; the spirit-world is vertical and cannot reproduce, so God needed Adam and Eve in physical form to populate the Kingdom of Heaven through their descendants.
Elaboration. SMM grounds the necessity of physical embodiment in spatial geometry: “Why did God create Adam and Eve as physical beings? The spirit world is a world of vertical relationships. It does not have horizontal dimensional space. There is no reproduction in the spirit world” (3.2. The people of heaven are created on the earth, 262-229, 1994.7.23). Earth is recast as God’s factory: “Planet earth is the production line for creating the people of the Kingdom of Heaven. People are not produced in the spirit world. They come from the earth … God created the earth that we live on as the factory to produce His people” (ibid, 201-44, 1990.2.28). The blessed marital family is a “branch factory” of the main Adam-Eve factory (ibid). The doctrinal payoff: childbearing within blessed marriage is not optional or merely personal — it is the central God-given mechanism by which the Kingdom of Heaven is populated. Birth control and single-life are correspondingly weighty refusals.