God is a missionary God. He is passionately committed to spreading his glory to all nations. So how should we define “missions?”
First, we must start with what missions is not. God commands his people serve the poor and hungry, but mercy ministry and social justice are not missions. If missions is reduced to providing relief, education, or compassion—in other words, if everything is missions—then nothing is.
Similarly, missions is more than sharing the gospel. If missions simply meant evangelism, then we could all do that in our hometown without crossing cultures.
To define missions, we must begin with the gospel, then work out to consider what God is doing in history.
The gospel is the good news of Jesus Christ’s death, resurrection, and reign to save sinners. This was necessary because, although all human cultures have knowledge of God through creation (Romans 1:19-20), every people group has rejected God (1:21-23) and is born in sin, trapped under God’s wrath (Ephesians 2:1-3). Since God’s standards of good and evil are written on every heart, all are accountable for their sin—even if they’ve never heard of Jesus or read the Bible (Romans 2:14-15). Humans in all cultures are equally lost, in need of rescue from an eternity in Hell.
The good news is that “God so loved the world, that he gave his only Son, that whoever believes in him should not perish but have eternal life” (John 3:16). Christ—the ultimate missionary—left the comforts of heaven, crossed into our world, died in our place, and rose in victory. Now all who repent and trust in Christ are made right with God and given eternal life.
What is God doing in history? At the onset of God’s redemptive plan, he promised that through Abraham “all the families of the earth shall be blessed” (Genesis 17:3). Jesus, the promised offspring from Abraham’s line, purchased “people for God from every tribe and language and people and nation” on the cross (Revelation 5:9). Right now, God is making a people for himself—bought by Jesus—from among the nations. We call that people the church.
Christ told his followers, “As the Father has sent me, even so I am sending you” (John 20:21). We are commanded to disciple all the nations (Matthew 28:18-20) until the earth is “full of the knowledge of the Lord as the waters cover the sea” (Isaiah 11:9). God’s work in history will be finished when all his people from every tribe and language are worshiping Christ in heaven (Revelation 5:9).
The gospel is the message God is using in history to save and set apart a people for himself in the church from every nationality, language, and ethnicity. Missions, then, is what carries this gospel to all the nations. It’s the job of the church that’s between Christ’s first coming and his return.
So what is missions? Missions is the task proclaiming the gospel to every people group that has not yet heard it, in order to establish churches—churches that will carry on mission by reaching their culture, teaching others, and sending missionaries out.