Every year, I teach my students about "cohesion," the ability of a substance to adhere to another substance -- water on glass, for example. And for the vocabulary-impaired students, I always emphasize the "co" part of the word... co-captains, co-workers, etc. Paul refers to cohesion in Romans 12 when he instructs believers that we are all part of one body, all having different functions, and each of these functions being necessary and equal. Obviously within a body of believers there are those who are more prominent or well-known, but in God's perspective, all members of the body function in roles that are equally important. Any one job not being done fully or properly is a detriment to the body of believers.
So what is my job? What is my role or function that is essential to others? I think most of us share the role of simply creating a support network for one another; and how do we best accomplish this? Paul answers this throughout his letters. First of all, in Romans 12, he admonishes us that we are all given a gift which we should use fully and wisely. In Galatians 6, Paul calls us to "bear each other's burdens" which is often taken to mean something like "when someone is going through rough times, you need to be there for that person." True. However, this verse in context means something more like "in whatever your friend is struggling spiritually, be a support and accountability partner." I could make some kind of biology joke about the membranes that hold all a body's tissues and organs in place... or I could simply say that each and every one of us who belongs to a body of believers should perform two functions by default: exercise our gifts as God gives us opportunity, and maintain accountability among our friends.