We should be dumbfounded at how doable the remaining task of world missions is. Before I show this, let’s clarify some definitions. Missions is not the same as evangelism. Evangelism is sharing the gospel with any unbelievers, and that work will never be done till Jesus comes. Missions, on the other hand, relates to people groups, not just people, and the number is finite and relatively stable — like the “every people, tongue, tribe, and nation” of Revelation 5:9.

So missions is crossing a culture, learning a language, and planting the church through preaching the gospel among people groups that have no churches strong enough to evangelize their group.

According to the Joshua Project (as of February 16) there are 16,598 people groups in the world. 7,165 of these are “unreached” (fewer than 2% evangelical).

Defining things somewhat differently, the research arm of the Southern Baptist International Missions Board estimates 11,310 people groups, of which 6,405 are unreached and 3,100 are “unengaged” (no evangelical mission effort to reach them is underway).

Does that number sound large to you? 3,100? These are the people groups yet to be pursued and penetrated with a missions effort. The number is, in fact, amazingly small compared to the resources available to us.

Consider these numbers from the January 2013 issue of The International Bulletin of Missionary Research (vol. 37, no. 1):

• There are 44,000 Christian denominations in the world — 14 for every unengaged people group.
• There are 700 million evangelical Christians in the world — 225,000 for every unengaged people group.
• There are 4.5 million Christian congregations in the world — 1,451 congregations for every unengaged people group.
• There are 4,900 Christian foreign mission sending agencies in the world — 1.5 agencies for every unengaged people group.

This is simply mindboggling. I am not unaware that most of these 3,100 unengaged peoples are in places and under regimes that are hostile to Christian presence. So I am not saying it will be easy to reach them. It will be very costly.

But if God would grant the passion and courage and wisdom, the remaining task is neither vague, nor enormous, nor unattainable. Would you join me in obeying Matthew 9:38, “Pray earnestly to the Lord of the harvest to send out laborers into his harvest”?

And then be a radical, sacrificial goer, or a radical, sacrificial sender. Jesus has all authority to accomplish this. He promises to be with us to the end of the age as we mobilize for this. What a thrilling prospect! What a cause to live for! What a holy ambition.

John Piper is founder and teacher of desiringGod.org. He served for 32 years as pastor of Bethlehem Baptist Church, Minneapolis, Minnesota. He is author of more than 50 books. John and his wife Noël have five children and twelve grandchildren. This article first appeared on Desiring God and is used with permission.