Explanations from Sun Myung Moon's speeches
Had Adam and Eve not fallen, then through perfecting themselves, they would have become God’s body and the king and queen of love. They would have fulfilled their portion of responsibility connecting the realms of direct and indirect dominion on earth through the love of God.
The realm of direct dominion is a place where Adam and Eve can participate together, united in love.
The place where parents and children, husband and wife, and brothers and sisters all want to join together in true love is the ideal family.
Eventually, therefore, the positions of above and below, left and right, and front and back, together with the one central point, form the number seven. Forming the number seven means to become one with God through perfect true love and to form a family in which everything becomes a perfect sphere and achieves harmony and unification.