In the Garden of Eden, at the very beginning of human life, God gave a simple instruction to Adam and Eve: “Be fruitful and multiply, and fill the earth and subdue it” (Gen 1:28). With this simple command, I believe God gave the most powerful theological and rational basis for evangelism and church growth. The prescriptive and normative interpretation of the command to procreate aside, God challenges humanity with the incredible task and blessing of passing on faith and relationship with God to subsequent generations.
Being fruitful is the act of an individual. In John 15, Jesus says that it is the glory of the Father that we bear much fruit. Paul lists nine fruit to born in the life of Christians in Galatians 5:22-23. As individuals, we are walking with Christ, allowing our hearts to be changed, bearing fruit that is evident to the world around us. Bearing fruit is the call to all people to exemplify Christ in the minute of human life. Christ-followers are on display to the world so much so that the fruit born by a Christian can win souls to Christ or stray them farther away.
Multiplying requires two people and is not simply adding people to the holding tank of church. Multiplying in the Christian walk means leading someone to Christ and discipling and equipping them to the extent that they themselves can lead someone else to Christ and pass on the equipping they received. Acts 2:41, 2:47, 5:14 and 11:24 all speak of dynamic addition to the church because of the work of the Holy Spirit in the lives of the apostles. God’s church is meant to grow! Like nuclear mitosis, multiplying Christians produce an exponential amount of fully-functioning, balanced, discipling, mission-drive, soul-seeking Christians that carry out the process even further.
Filling the earth is the act of the community. Left alone, a single firefighter cannot quench a roaring wildfire. Yet, with help from his or her firefighter pals, the fire can be subdued fairly quickly. As we come together in communities, churches, and institutions, resources are made available and the gospel work is allowed to exponentially grow throughout the whole world because we are united together in mission work. This filling of the earth erupts into subduing the whole earth, not in a coercive manner but in a way that brings everyone into the multiplication of disciples that produce kingdom people.
Church growth and evangelism require all three components to pay dividends in the kingdom. For a church to grow, you need sold-out Christians who are bearing the gospel fruit. For a church to grow, you need multiplying Christians who are ready to disciple and train others to multiply results. For a church to grow, you need a community that is willing to come together, accepting new sheep into the fold and providing resources for those bringing in new sheep.