Christ is the head of His body (Colossians 1:18). That is what makes the church His body. There is only one body (Ephesians 4:4), thus there can only be one head. A body with two heads is a monster, but a body with one head is beautiful. The physical body is for the purpose of containing and manifesting life, and it is no different in the Body of Christ. The body reveals life under the direction of the head. The arm obeys the head and assists in carrying out the purpose of the head. The arm, however, does not give direction to the rest of the body. "Now you are the body of Christ, and members individually" (I Corinthians 12:27). This we are in reality by the grace of God, but we are not the Head. We are called to give expression to the life of God as directed by the Head, but regardless of our function in the body, whether it be as an eye or a toe, we never take the place of the Head and give direction on our own. The revelation of Christ as the Head of His body, with the members being in subjection to the head and moving under the direction of the head, is the foundation for seeing how spiritual authority works out in reality in the church, the body of Christ.
If we are to see clearly that the only authority that is to be manifested in the Body of Christ is spiritual authority, we must first see clearly that the body is a container or vessel of the life of God. "Do you not know that your body is a temple of the Holy Spirit who is in you, whom you have from God, and you are not your own?" (I Corinthians 6:20). "I have been crucified with Christ; it is no longer I who live, but Christ lives in me..." (Galatians 2:20). It is "Christ in you, the hope of glory" (Colossians 1:27). The purpose of God is that He may be all in all and fill all, and that begins with those who have come for cleansing to Calvary. Salvation is not just to be cleansed from sin, but to be filled with God. "And the glory which You gave Me I have given them, that they may be one just as We are one: I in them, and You in Me; that they may be made perfect in one, and that the world may know that You have sent Me, and have loved them as You have loved Me" (John 17:22,23). The purpose of God is union--God indwelling man. Thus each member that is alive unto God is a vessel of His life. Every manifestation is to be the life of God--His nature, His holiness, His character, His very person. The life is revealed through distinct individuals, but it is a common life being manifested, coming from one source.
As we keep in mind the truth that it is His life being manifested through every member, it will give us understanding as we consider some of the different functions in the body, for we will be able to see that it is only the authority of His life flowing through each member that is spiritual authority.
One area which we may think of quickly when we think of authority is eldership. Elders are appointed by God (Acts 20:28) with grace (or ability) to carry out the task of overseeing, or giving guidance to the flock as the Holy Spirit would direct. But notice that they only have authority as they manifest the life of God. Should they fail the qualifications (I Timothy 3), or not speak the mind of God (I Peter 4:11), there is no authority. Paul could say, "Follow me as I follow Christ," but should he turn aside, all authority flowing through him up to that point would cease, because authority is in the life of God under the direction of the Head.
Authority, as we have already seen, is not vested in the man, but in Christ, and only seen as we are in union with Christ. God speaks His mind through men in leadership, but those men never take the place of the Head. They never occupy an office which carries authority until the end of its term. Even though God may have called a man and given him grace to function as an elder, that man's only authority whether he has functioned for one day or 40 years is that he is a vessel through whom the life of God is flowing. When that life ceases to flow for any reason, all authority ceases at that point, and he is not recognized by God. He functions as an ambassador, never as the Head.
What is true of elders is also true of every other member of the body. Those who give public leadership are perhaps more noticed due to the nature of their function in the body. But what is true for public leadership is also true for each member: "submitting to one another in the fear of God..." (Ephesians 5:21) "Wives, submit to your own husbands, as to the Lord" (Ephesians 5:22). It is always as unto the Lord. We submit to and obey the direction coming from the Head. It comes through the members, but it comes from the Head. It is because the direction is from the Head that we submit and obey. The burden is always twofold. The command to one giving the direction is "you who are spiritual" and "speak as an oracle of God." The command to the one receiving is "recognize and obey those who have the rule over you" and realize that the hand of God is flowing through the other members to feed us. We are all always giving and receiving. If we have this attitude of mind and heart, it leaves us open to receive and give, building up one another in the fear of God.