Claim. A wedding is the bequeathal of love from parent to child; officiation by true-parents is therefore not ceremonial preference but principial necessity, while officiation by an eminent outsider stands in for the archangel.
Elaboration. SMM states the rule and its rationale together: “In the Garden of Eden, the weddings of the sons and daughters of Adam and Eve should have been conducted by Adam and Eve themselves, under the guidance of God. Our weddings should also be conducted in the same manner. That is why in the Unification Church, the Blessing Ceremony is conducted in the name of True Parents” (1.1. What is the Blessing?, 96-236, 1978.1.22). The negative case is sharp: “Weddings not officiated by the parents are officiated by the archangel. When an eminent person comes to officiate at a wedding, alone, like an odd shoe, he is conducting the wedding as the archangel” (ibid). The wedding is “the bequeathal ceremony in which you receive this love from your parents … you receive the love of God from your parents.” A wedding without a True Parent therefore re-runs the archangel’s wrongful intervention.
See also. true-parents, blessing