Especially for God to be a Person, He must always have had and always continue to have a Face or Prosopon or a Divine Personality — always interfacing with other Faces or Prosopa or Divine Personalities. Also tritheistic Mormons deny this. For their "Father" and "Son" and "Spirit" are not one but three different gods — not co-eternal, but emerging consecutively and accumulatingly in an endless polytheistic series.
The Church-of-the-future will need to set out, also in the various inter-relationships of human society — the full implications of the Father's paternity, the Son's filiation, and the Spirit's procession. For the Church needs to distinguish the various personal attributes of the Deity ontically (within Himself) — from their application economically (within man's world).