This is based on the view of the body described in I Corinthians 12. Paul informs us that every member of the body is important. The body will not function properly unless all body parts are healthy and active. None are ignored. None are more important than others. In order for the body to do what it is supposed to do, every part must be up and running.
For this to occur the body as a whole has to trust the lead of the Holy Spirit. The Spirit not only bestows spiritual gifts, but also leads believers into using these gifts. The body must respond to the Spirit's leading by encouraging everyone to use their own gifts actively for the building up of the entire body. Everybody matters.
One place many churches (regardless of form) fail is in encouraging everyone to be active. It's easy to simply let some folks sort of sit quietly in the background and not do much. If this happens the body will suffer - possibly in ways it hasn't really considered. Since I Cor. 12 is true, then everybody needs everybody. We the church must get the message out that every believer has the responsibility to be active. Let's not guilt one another in this, but instead encourage each other. Ironically, this means we will be encouraging each other to encourage each other.
The church is stunted when a small number of people do most of the ministry. That model makes for a sick body, where some parts are overworked and others are undeveloped. Much healthier is a body where every part is in shape from regular exercise. Let's all do our part by using our gifts to serve and encouraging others to do so.