The Words of the Kurtz Family
The bow is common place in many Eastern cultures. It was also commonplace in the West in days gone by. It is a gesture of respect or reverence, and most notably in both the East and West it is/was meant to indicate a hierarchy; an order.
And so it is in the Unification Church. It is an expression of reverence and denotes a proper order. All bow to the True Parents, as well as children to their own parents. And the True Parents represent God as Jesus commanded all to "be perfect as God is perfect." This is in line with the Unification Church teaching that no fall could be imagined or planned by God and that we were all meant to grow as loving families; the couple, the unity of husband and wife being God's image on earth. Had Adam and Eve not fallen they would have embodied God (as we all are meant to embody God) and established God's lineage, and being the beginning point would receive the greatest respect, equal to that of God. Their family, their heart towards all mankind as their substantial children, would stand unique and irreplaceable above all.
That new beginning point, which should have been held by Jesus if he had not been killed and married, represents God and is shown reverence. This is the goal of all of history and is the significance of True Parents.
So bowing is a powerful part of the Unification Church culture. It may be compared to genuflecting or a priest lying prostate before the alter.
It is also practiced as an offering. Like one may say a rosary or set a certain time to pray for a certain set period, offering bows has become a similar practice. Not as easy as one would think if you are bowing tens of times a day. It may be compared to those who will travel on pilgrimages barefoot or crawling on one's knees. One can see monks and others in a continuous series of bows at Buddhist temples, somewhat similar to a Sufi Dervish whirling, though the intent of the practices are necessarily the same.
Such acts of devotion or contrition are far from uncommon in religious traditions. The motives and goals are often inconceivable to many, as they may witness these prostrations along a pilgrimage route or at some shrine, but usually are highly respected by most.