A friend wrote, "I heard this today and am still thinking about it. "Belonging, by nature, divides us." What do you think?"
What a stimulating question!
1) First, I think we need to define what we mean by the term "belonging."
ISTM that there are two ways of belonging: to a community, or as part of a collection. The Trinity is a community. The Three Persons "belong" to the one substance, God; so there is difference, but without division. All three Persons are distinct (the Father is not the Son, the Son is not the Spirit, the Spirit is not the Father) but all three persons are united in their will because they are united in their nature, as God (Sometimes people point to Luke 22:42 to say that Christ's will is different from the Father's, but I think that verse shows just the reverse. Jesus's will is always in harmony with the Father's! )
But ever since the late middle ages, Western thought has been infected by nominalism, which says only particular individuals are real, not universals. The atomistic individual is autonomous. That means the first sort of belonging, to a community, becomes impossible. One can only be part of a collection of autonomous individuals--so the belonging is not grounded in any "reality," but only in will ( I CHOOSE to identify with this collection/group). There is no shared "nature," so there is no shared will. That sort of "belonging" is a recipe for division. That "belonging" can only be temporary and for pragmatic reasons. As soon as an individual decides s/he wants something different from the group, or identifies with a different group, unity is broken. We are in Judges 21:25 and Isaiah 53:6 territory.
I do not believe the unity/ community of the Trinity can ever be broken. (For the reasons why, see Thomas H. McCall, "Forsaken." http://www.amazon.com/Forsaken-The-Trinity.../dp/0830839585 )
2) Thus, to answer your original question: if we understand "belonging" in the *realist* rather than the *nominalist* sense, belonging does NOT divide us. But if we define "belonging" in a nominalist sense, then yes, belonging DOES divide us.