World missions and church reform should not be separated. They go together. Simply put, they are friends.
All we have to do is read the New Testament to see that church reform and world missions go together. In the gospels Jesus instructs us in how to live (reform) and in the importance of taking the gospel around the globe (missions). In the book of Acts we see the church live holy lives in the midst of pagan societies (reform) and preach the good news of Christ in ever expanding areas (missions). In the epistles we read much exhortation to holy living. We also read about what the church is, what it should do, how it should be shaped, and how it should function. The letters are seeking reform among the recipients. The epistles also have missions themes running through them from beginning to end.
Church reform and missions go hand-in-hand today as well. For example, when churches decide to reform the way they spend money to come more in line with scripture, they will likely have much more money to give toward world missions. This is a huge benefit to the cause of taking the gospel overseas. Also, when churches decide to obey all aspects of scripture, they must take the Great Commission seriously. When churches are deliberate about following not only what is commanded but also what is modeled, they will take a simple form of church life to the new converts overseas.
New believers, regardless of where they live, need to unite with other Christians. The best way to do this, especially in countries where Christians face persecution, is the simple way. Simple church concepts, which we see modeled for us in the bible, make forming a church easy (at least as far as the structures and forms are concerned). Most lost people overseas are very poor. They cannot afford big buildings or salaried clergy. If they follow simple church ideas, they won't have to be bothered with these things.
Ultimately, both church reform and world missions honor God by being obedient to what he has shown us in the bible. The two go together. When the church comes more in line here with what we see in scripture, the church can be more effective overseas in spreading the gospel and planting churches.
Let's be a part of both conversations and actions.