Luther famously addressed the Diet of Worms in 1521, “My conscience is captive to the Word of God.” Indeed, central to the Reformation was the idea of sola scriptura, the idea that the Scriptures alone are authoritative and sufficient for both faith and practice. This doctrine was contra the teaching of the Roman Catholic Church, which held that Scripture was equal in authority and infallibility with the teaching and tradition of the Church. Luther and the other Reformers believed that only the Bible authoritatively and infallibly revealed what we must believe to be saved and all that we must do to glorify God with our lives.
This central Reformation tenet continues to have ongoing importance in the evangelical church today. Those involved in cross-cultural missions need to understand the implications of this doctrine as they take the gospel to the end of the earth, plant churches, and train leaders. While there are many implications of sola scriptura for the missionary today, let’s consider three.
While much confusion surrounds the idea of contextualization in missions, it can be simply defined as “making the gospel clear.” Understanding that wherever we go in the world, there are going to be people who speak different languages and have different cultures, worldviews, and beliefs than our own. In order to clearly articulate the gospel in these contexts, we must adjust the way we deliver the message.
This does not mean that we change the message of the gospel. Some criticize efforts of contextualization, claiming that it will distort the gospel message. Yet, if we fail to contextualize, we will most certainly distort the gospel message. For instance, if we want to reach an uncontacted tribe in the Amazon jungle, we recognize that speaking the gospel in English or German is insufficient. Rather, we would need to learn the language of this tribe so that the words of life can be heard and understood. This desire to be heard and understood is the very point of contextualization.
What does that have to do with sola scriptura? It is possible to enter any people group and bring along more cultural baggage than we realize. Because we believe the Bible alone is the authority in the Christian life, we need to labor diligently to make sure our message has shed the unnecessary baggage of our home culture. We must evaluate our methods to ensure that what we are calling people to repentance and faith and not repentance and Western culture. We must ensure that our discipleship and leadership training is not requiring something of leaders that the Bible does not.
The task of a missionary is to make sure we are communicating “Scripture alone” through contextualization.
The goal of much missionary strategy is to leave behind churches that are self-governing, self-supporting, and self-propagating. This means that the way we share the gospel, plant churches, and train leaders must be reproducible. Roland Allen noted many years ago that methods that tried to duplicate Christianity in another context stunted the growth of the church in missions contexts. Giving the impression that Western style church buildings, dress, or even furniture were required for churches produced an unreproducible model of church life.
Instead, armed with sola scriptura, we can gather believers around the Word of God in whatever kind of building or furniture that is readily available in that context. The minute we add a requirement (whether implicitly or explicitly) that is not in Scripture, we keep church ministry from being reproducible.
The same is true in discipleship and leadership training. Around the world, there are countless churches who lack a pastor because an unbiblical leadership requirement was unwittingly added, many times by the original missionaries. Requiring a man to leave his home village to attend seminary for four years in an urban setting is certainly not a biblical requirement and slows reproducibility. Even non-formal leadership training must be done with the intent to be passed on or reproduced easily. Surely this is the point behind 2 Timothy 2:2. Ensuring that our methods and requirements for church planting, discipleship, and leadership training are Biblical is right and good in and of itself. Further, a biblical methodology allows our efforts not to end with our ministry. Rather, armed with Scripture alone, these efforts can be reproduced for generations to come.
In 1 Corinthians 3, Paul reminds the Corinthians that he laid the foundation of the gospel and that it is now being built upon by others. Because Paul’s foundation was Jesus Christ, no one could have laid a better foundation than he did. So long as those who come after him build something in accordance with that foundation, “he will receive a reward” (1 Cor 3:14). Imagine then, as the gospel is taken into previously unreached places, how important it is that cross-cultural workers lay the foundation of Jesus Christ and nothing else. Imagine how important it is that they take nothing with them but Scripture alone. If the truth is mixed or syncretized with any thing else, it would not only damage that current generation, but it could spread a false gospel for years to come.
I was reminded of this reality several months ago when I met a church planter in a small village three hours from where I live in central Argentina. It’s the kind of village that you only encounter if you mean to go there. It requires driving on several dirt roads until the point that you’re sure you’re lost. Electricity only recently arrived to this village, and clean drinking water remains an issue. There is a small Catholic chapel in the village, but the priest comes only to marry and bury. Before this church planter’s family arrived, there was no Bible teaching or Christian activity of any kind. This brother has been a believer for several years and was trained in a Bible institute before moving to this village. His church planting work has been slow and difficult, but he and his family have labored faithfully. As I watched this brother teach from the Bible to his small but eager congregation, I praised God for his Bible training. This man is the only source of Biblical truth for many miles. If he were to lay a foundation other than Jesus Christ, or with Jesus Christ-plus-something, not only would this brother lead these villagers astray, he could also do generational damage. Yet, armed with belief in the authority of Scripture and a foundation with which no rival can compete, this brother remains a generational lighthouse of truth in this village.
Luther and the Reformers devoted their lives to a movement that refocused the church on the authority of Scripture. Today, missionaries can honor their labors by ensuring our strategies and methods submit to sola scriptura, to the authority and sufficiency of the Scripture alone.
 Roland Allen, Missionary Methods: St. Paul’s or Ours?