Just recently True Mother stopped using two separate chairs for her and True Father in public gatherings. She instead now uses one chair to sit, perhaps giving the impression there was no chair for True Father.
But her reason for the use of only one chair was explained publicly by a Korean leader: it is that God, True Father (Rev. Sun Myung Moon) and True Mother (Mrs. Hak Ja Han Moon) have already become completely one, constituting a Trinity. To me, it makes sense. Only one chair would be needed as long as the Trinity of God, True Father and True Mother is there.
Perhaps the traditional Christian doctrine of the Trinity, which shows how the three persons of the Father, the Son and the Holy Spirit are united in the Trinity, can help us understand how God, True Father and True Mother are united in their Trinity.
A first way how the traditional Christian doctrine of the Trinity describes the unity of the three persons is by talking about their “mutual indwelling” or “interpenetration” (perichoresis in Greek; circumincessio in Latin), and it is supported by Jesus’ own words: “I am in the Father and the Father in me” (John 14:11).
While this Greek term, perichoresis, was originally used to describe the relationship of unity between the divine and human natures of Christ, St. John of Damascus (c. 676-749) for the first time extended it to the Trinitarian unity in the sense of mutual indwelling or interpenetration, and its Latin translation, circumincessio, came later. Whether in Greek or Latin, it became a technical term for the Trinitarian relationship in the above sense. In the same way, we can perhaps say that God, True Father and True Mother, in their Trinity, have the relationship of mutual indwelling or interpenetration.
A second way the traditional Christian doctrine of the Trinity describes the unity of the three persons concerns their “outward operations” (opera trinitatis ad extra) in the divine economy. Usually considered to have come from St. Augustine (354-430), it says that the three outward operations of “creation,” “redemption” and “sanctification” in the divine economy, which may be attributed primarily to the Father, the Son and the Holy Spirit, respectively, are nevertheless “indivisible” (opera trinitatis ad extra indivisa sunt), so that all three persons are involved in each of these outward operations.
This means the Son and the Holy Spirit, too, are involved in the operation of “creation,” which is attributed primarily to the Father; that the Father and the Holy Spirit, too, are involved in the operation of “redemption,” which is attributed primarily to the Son; and that the Father and the Son, too, are involved in the operation of “sanctification,” which is attributed primarily to the Holy Spirit.