Romans 10 says (v. 8-15):

“The word is near you; it is in your mouth and in your heart,” that is, the message concerning faith that we proclaim: 9 If you declare with your mouth, “Jesus is Lord,”and believe in your heart that God raised him from the dead, you will be saved. 10 For it is with your heart that you believe and are justified, and it is with your mouth that you profess your faith and are saved. As Scripture says, “Anyone who believes in him will never be put to shame.” For there is no difference between Jew and Gentile—the same Lord is Lord of all and richly blesses all who call on him, for, “Everyone who calls on the name of the Lord will be saved.” How, then, can they call on the one they have not believed in? And how can they believe in the one of whom they have not heard? And how can they hear without someone preaching to them? And how can anyone preach unless they are sent? As it is written: “How beautiful are the feet of those who bring good news!”

This mirrors the Great Commission of Matthew 28 (and other passages) where Jesus commands us to “go” into all the world and proclaim the Gospel, making disciples of all the nations.

While we realize that Finishing the Task does not mean everyone will believe, it does mean we must give the opportunity to follow Christ. And since we don’t know who will accept this opportunity, no one can be left out from the giving.

Therefore, all must hear. Which means they must have something to hear, and someone to hear it from.

The problems we face in making sure every single individual alive on the planet right now has heard the Gospel at least once in their lifetime are enormous. They have, in fact, kept us from achieving this goal so far.

But “everyone hearing the Gospel at least once in their lifetime” isn’t (probably) the “Finish the Task” line–not technically. Because we can’t be just about the people alive on the planet right now. We have to think about the people who will be born in the future!

The idea of “sustainable closure” is this: we can’t expect to easily reach a point in time where everyone has heard – at least not in the near future. So, let’s say a mission effort “evangelizes” all of Nepal. Tremendous! Everyone has heard the Gospel! Now, a parallel effort is working to do the same thing in India, Pakistan, and Afghanistan. But, the challenges are far greater in those places (persecution, restriction, larger populations). In the same year that Nepal was evangelized, babies were born. In the years it took for Afghanistan, India, and Pakistan to be evangelized, those babies have grown up. If we rely on a successful one-time mission campaigns to evangelize a place, the campaigns will have to be repeated every five to ten years for the children that were born in the interim.

The definition of “unreached” captures the idea that the job is done when there is a church able to evangelize each successive generation.

The “task” must be finished over and over again in each place until all the places are finished. This is why the missionary task is not evangelizing people but the planting of local, indigenous, contextualized ekklesia communities that are capable of evangelizing the people.

When we mix up the missionary task and make it all about presenting the message to the most people we can within the limited time we have (whether it is 2 weeks, 2 years, 4 years, 20 years or a lifetime), the net result is a missionary extracted from the big picture, who makes eternal difference to some but cannot make an eternal difference to the many who come after. This is good work for those he reaches, but does nothing to the grand “finishing of the task” which will be important to billions.

Note: I do not think this is all that Finishing the Task means.