You asked: I don't understand what the papers mean when they say: 1. Mother-son, 2.The Son-Spirit, 3.Father-Son. Could you please explain each one and their meaning?
Thanks so much for your question to us here at TruthBook.
Your question turned out to be a distinct challenge for me; even though I am a long-time reader/believer, it was a head-scratcher! Fortunately, I was able to pick the brain of another reader - a good spiritual brother who is a real Urantia Book scholar, in my opinion. There's always something new to learn!
His reply follows:
The designations "the Father", "the Son", "the Spirit", and "the Mother" each indicate a particular facet of Deity. "God" is personalized Deity; so the personalization of each of these facets is designated "God the Father", "God the Son", "God the Spirit", and "God the Mother". Since Deity is more fundamental than God (the personalization of Deity), Deity transcends the "individuality" of any of its personalizations, for example, the individual who is designated "the Universal Father". The fundamental quality of Deity is "unity". The various phases of Deity are best called "facets", because they are like distinct faces of one crystal. From the unity viewpoint, God is one; even though, from the individuality viewpoint, God is many.
Personalities "act", but Deity "functions"; and since Deity transcends individuality, Deity does not merely function as separate facets. For instance, two facets of Deity can function together as one. This is indicated in the revelation by hyphenating two facet names together as one compound name, for example, "the Son-Spirit". The functioning of this Deity is different than that of the Son or the Spirit or the sum of the two; it is a superadditive combination. Also, the order in the compound name is significant: the second element is the foundation. For example, with the Deity of the Eternal Mother Son, "the Mother-Son", the experiential Deity of "the Mother" is an augmentation of the foundational, existential Deity of "the Son"; because the (preexistent) Eternal Son acquired experience in the central universe and became the Eternal Mother Son. Likewise, the Deity of "the Father" and the Deity of "the Son", together as one, with the Son as the foundation, can be personalized as an individual--a Creator Son. However, the Deity of "the Father-Son" also functions beyond any individual Gods.
So, there you have it...
I want to thank you again for your thought-provoking inquiry. Reading this answer proved to be an eye-opening lesson for me. I hope that it is satisfying to you as well...
Please feel free to write back any time!