There is a lot of discussion in the church world about how the church ought to grow. My own training as a pastor was steeped in this approach: if the church of God preaches the Word and the Gospel faithfully, worships God biblically, and seeks to grow its members so that their character is conformed to Christ then the church will grow. "Healthy things grow" is the mantra. To a large degree the church health approach to ministry is on target. God has determined how ministry is to be done in His church. If you depart from His instruction in your goals or your methods for ministry your church members will not be spiritually healthy. Unhealthy people will have unhealthy testimonies. They will not have the hope of the gospel animating their lives. They will not be unhealthy because they struggle with sin (indeed, the more healthy they become the more they will endeavor to live for Christ and struggle with sin), but because they do not experience grace in their struggle. They will be joyless, dour and fruitless--that's not much of a witness to the world to show that the gospel is the power of God for salvation (Romans 1:16-17).
However, we need a bit more than an a call to "church health" to fulfill the Great Commission. Christ called his church to fulfill a mission in the world (Matthew 28:18-20). Often when we consider the Great Commission we emphasize the "go" part as if that is the heart of the command. The heart of the command is the "make disciples" part. Putting on our high school grammar hats we would put it this way: the "go" in the great commission is a participle. (Some say that it has imperative force, but nevertheless it is a participle.) The true blue imperative in the Great Commission is the "make disciples." The "go" tells us the manner in which we will be making disciples. The church will be on the move making disciples.
To be on the move means that plans and strategies must be developed in faithfulness to the Great Commission. "Where are we to go?" "We have the means (the Gospel and the Word) but how exactly are we going to employ them outside of worship on Sunday?"
If the church is not making disciples according to God's plan and with God's means then it is not healthy. But if church is not making disciples "on the move" then it needs to get on the move. I think it best to put down the division between being a missional church and a health church. We really cannot be one without being the other.