For all the talk about church health, possibly the most underutilized resource is that of the book of Ephesians which is, if nothing else, a primer on church health. Unlike many of the other churches in the New Testament, the church at Ephesus was a pretty healthy body.
In fact, I would suggest that Ephesus was a great example of a church of "irresistible influence." A reading of Acts 19 shows that this church was instrumental in the name of Jesus becoming known throughout the whole region and the gospel was so powerfully proclaimed that real persecution evolved. But in the midst of that, there was a level of public repentance for sin rarely seen and "the name of Jesus was held in high honor" (Acts 19:17).
Paul's farewell to the Ephesian elders (Acts 21) at a later time indicates that he had left in that church a group of committed, courageous and theologically trained leaders.
Then move to the book of Ephesians itself. Several things stand out as it relates to what a healthy church looks like.
First, healthy churches result in real life transformation. This transformation is rooted in a true and transformational understanding of one's life in Christ (Ephesians 1 and 2). This is a transformation so profound that it changes the outlook of those who have experienced it on ourselves, on God, on relationships, on other racial groups, on how we live, our marriage relationships, family relationships, unity among other believers and our view of the the spiritual war taking place behind the scenes around us.
While we have often stressed certain life changes (all good) we have often not stressed that this life change is rooted in a radical transformation that comes from a relationship with Jesus Christ. Our goal in the church is not to help people look like whatever we think Christians should look like but the radical reorientation of their life that comes out of new life in Christ.
This radical reorientation of life is accompanied by a power for living that Christ brings. In his prayer for the Ephesians in 3:14-21, Paul uses the word three times, once in each of his three main thoughts. The Christian life is only possible through the power that comes with the Holy Spirit and is likened to the power that ripped Christ from the grave and seated him at the right hand of God in 3:1-13.
The book of Ephesians also makes it clear that it is the church that is God's chosen instrument to reach the world. "His intent was that now, through the church, the manifold wisdom of God should be made known to the rulers and authorities in the heavenly realms, according to his eternal purpose which he accomplished in Christ Jesus our Lord (Ephesians 3:10-11)." The church is His bride and is loved as a husband loves his wife (chapter 5).
If, indeed the church is His chosen instrument to reach the world, the transformational nature of the church, the unity of the church and the church as an equipper of His people (Chapter 4) becomes of primary importance
Unity in the church is an underrated issue that has huge implications for whether a church will impact the world around it. That is why Paul tells us to "make every effort to keep the unity of the Spirit through the bond of peace. There is one body and one Spirit - just as you were called to one hope when you were called - one Lord, one faith one baptism; one God and Father of all, who is over all and through all and in all (Ephesians 4:3-6).
In his farewell to the Ephesians elders in Acts 21, Paul specifically charged the leaders to be on their guard against those who would come in and divide the church. In fact, divisive people are one of the great threats to the the Church. Ironically, modern day evangelicals are quick to guard the church against heresy and perhaps ongoing unrepentant sin but we allow divisive people to continue their spoiling of Christ's unity with impunity.
The purpose of church leaders is not to do the work of the ministry but to prepare His followers for works of service so that the body of Christ may be built up (Ephesians 4:12). Bringing God's people to the place where they are using their gifts and wiring of Him is a prerequisite of maturity (Ephesians 4:13) and it is to the extent that a majority of His people are engaged in His work that the congregation itself will become mature (Ephesians 4:16).
This is rooted in the understanding of Ephesians 2:10 that "We are God's workmanship, created in Christ Jesus to do good works, which God prepared in advance for us to do." We were created both for relationship with Christ and to do work for Christ. It is my conviction that the reason the church has so little influence outside its four walls today is that we have not take seriously this call on every believer to be engaged in His work and rather than equipping people for ministry, many staff positions are simply doing the ministry on behalf of everyone else. That is not a strategy that will yield great influence, nor maturity.
Ephesians 4:17-5:21 goes back to the theme of transformation but this time in very practical ways. The life we have entered into in Christ gives us the responsibility to "put off" all kinds of practices and attitudes that are at odds with our new life and "put on" those practices and attitudes that would reflect our new life with Christ. Thus, transformation brings intentional change in our thoughts, motives, and the outworking of our faith.
The numerous surveys that show that the behavior of those who claim to be Christ followers compared to those who do not indicates that such life change is not taking place today. Of course, the church may not be explicit today that such behavioral changes are non negotiables if we are going to follow Jesus fully.
There is no greater passage on spiritual warfare and the need to live in the full power of the Holy Spirit and the Word than that of Ephesians 6:10-18. This passage gives us a small peak behind the veil of our world to see what is going on beyond our sight but in our presence in the spiritual realms.
My view is that God's people generally do not have an adequate understanding of this very real spiritual war that is taking place or the need for all of God's armor in order to fight that war. To the extent that we understand God's divine drama and the war between the forces of good and evil, to that extent we will armor ourselves for that conflict.
The bottom line is that the book of Ephesians is a fundamental treatise on the health of the church. Boards that will take the time to study Ephesians and ask the hard questions about their own church and people will benefit greatly. It will be far more important than any book they could read on church health. It is the fundamental treatise on church health in the New Testament.