" But to each one of us grace was given according to the measure of Christ's gift. Therefore it says, "When He ascended on high, He led captive a host of captives, And He gave gifts to men . . . And He gave some as apostles, and some as prophets, and some as evangelists, and some as pastors and teachers, (Eph 4:7-11)"
As Paul continues his discussion on unity in Ephesians four, he delineates how individual people in the church fit in.
First, he speaks of the leaders who teach and shepherd the congregation. His first point he makes concerning them is that the leaders are put there as Christ's gift. The military imagery this texts uses is appropriate. After Jesus triumphed at the grave, he led a victory procession and gave out gifts. He didn't just liberate us and leave us to our own devices. He gave the gift of leaders in the church to continue to guide us.
He goes on to describe what the purpose is for these "gifts."
"for the equipping of the saints for the work of service, to the building up of the body of Christ; until we all attain to the unity of the faith, and of the knowledge of the Son of God, to a mature man, to the measure of the stature which belongs to the fullness of Christ (Eph 4:12-13)."
So the leaders have a both a right and responsibility to monitor our spiritual health. The goal is spiritual maturity. When the church is growing, the church is healthy. When the individual members are "building" up the body through "works of service," the church will be unified and healthy. But it is not just the responsibility of the leaders to promote church health. It is everyone's responsibility. The leaders cannot and should not have to do it all by themselves. That is why this text also says this...
" but speaking the truth in love, we are to grow up in all aspects into Him who is the head, even Christ, from whom the whole body, being fitted and held together by what every joint supplies, according to the proper working of each individual part, causes the growth of the body for the building up of itself in love (Eph 4:15-16)."
Fitting together in unity comes from "what every joint supplies." So the unity of the church has an attitudinal basis, a theological basis, and also a sacrificial basis. When we put others ahead of ourselves and serve, when "each individual part" causes the growth of the body for the building up of itself in love, then the church will be what it is supposed to be as a witness to God in the world.