Scripture calls believers the body of Christ. We are to function as one unit, each finger, toe and arm doing its job. We are each others joints and ligaments (Colossians 2:18-19).
A ligament is a tough fibrous band connecting extremity bones and holding organs in place. Joints are the point of contact between elements of a skeleton that surround and support it. With these dictionary based definitions, we can more easily determine our relationship to other Christians. We are to support and work in unity with them.
Note Paul places the illustration in contrast to the worship of angels and false humility, "not holding onto the head from which the body is nourished. Basing beliefs on visions and private revelations puffs up the individual essentially separating him or her from everyone else.
