What is center of Mass?

I am a grad student in Math and Engineering, and recently learned that the earth does NOT orbit the Sun as most people think, but rather a geometric point called the "center of mass" of the solar system, which is distinct from the center of the sun (but very close to it). Capitalizing the "M," what is the "center of Mass" for the church? Is it us? or is it God?


P.S. I like your usual homily. However, you forgot to include the words "ministry" and "witness" in at least every grammatical combination possible. (May I suggest: Our ministry of witness is to minister as witnesses to the ministry of the gospel of witness.")