Claim. No one born of fallen lineage can enter heaven without passing through the True Parents — the path through them is the one gate, while there are two hells.
Elaboration. SMM is uncompromising on the singularity of the gate: “There are two hells: one on earth and one in the spirit world, but there is only one gate to heaven… You can only enter through the True Parents; you need to pass through them to enter that one gate into heaven” (CSG 15.3 §4, 294-103, 1998.6.14). The lineage exclusivity is even sharper: “Of all human beings born on earth, not one was born from true parents. There is no way for those who were born without inheriting the True Parents’ lineage to enter heaven” (250-49, 1993.10.11). The Blessing is the operational entry condition: “Through marriage itself you may inherit your parents’ love. Due to the Fall, however, you didn’t inherit the true lineage. This is possible only through the Blessing… you need to be grafted anew to the True Parents to inherit a new true lineage” (162-63, 1987.3.27). The grafting is conducted under the Unification Church Blessing — not the secular wedding.
See also. csg-rebirth-requires-true-parents-not-fallen-parents, blessing