Three Spheres of Christian Activity. What God has asked the believer to do (i.e. Christian activity) can be largely divided into three spheres: office, gift, and priesthood. When all of these spheres are maintained in their proper order, the result is the God is glorified and His people are blessed. There is a danger of of confusing the various spheres of activity, and this can lead to serious trouble.
There is some similarity between office and gift (e.g. pastor is a gift, overseer is an office), yet the three spheres are kept distinct in scripture. For instance, gift is for the whole body, but office is limited to the local assembly. In fact, the Catholic system is the product of confusing all three spheres: gift, office, and priesthood!