The ‘10/40 Window’ is a fairly well known ‘shorthand’ or abbreviation for a region of the world where most of the unreached live. It gets its name from a ‘box’ that can be drawn on a map: from 10 degrees north to 40 degrees north of the equator, and from the western coast of Africa to the eastern coast of Asia. This includes most of North Africa, the Middle East, and Asia.This area has been called many names over time, although ‘The 10/40 Window’ has been perhaps the most popular. It was once referred to as the ‘Resistant Belt,’ although it is not so much resistant as simply unreached. The World Christian Encyclopedia refers to it as ‘World A,’ though there is nuance: ‘World A’ is defined in terms of countries, provinces, cities, peoples and languages; and if mapped, would include much of Indonesia (which is not ‘inside’ the Window). An old brochure by the AD 2000 & Beyond Movement did much to popularize the idea of the 10/40 Window; you can still see the text online at this link. At the time, 97% of the least-evangelized lived inside the Window—and that hasn’t changed significantly since. Is the 10/40 Window still useful today? In 1975, when Dr. Ralph Winter took the stage at Lausanne and called the unreached the highest priority of mission, he noted that 87% of Muslims, Hindus and Buddhists were beyond the reach of near-culture (E-1) evangelism—they needed cross-cultural mission if they were to hear the Gospel at all. Today, 85% of Muslims, Hindus and Buddhists still have no personal contact with a believer; if they are to hear the Gospel at all, it will have to be by cross-cultural witness. Since the 1990s when the 10/40 Window was popularized, much has been happened: there are large churches in China, India, Iran and Indonesia, and over 100 movements to Christ. But most of these churches, while large, are a ‘drop in the bucket’ compared to the immense population of the Window: over 2 billion people. The need the Window captures is still great. However, the Window does have a weakness (which the ‘World A’ methodology tried to avoid): it is geographically centered. Peoples, cities, and works are either ‘inside’ or ‘outside’ the Window. The 'fixed' nature of the Window can lead to some idiosyncracies: for example, in the following map, note how Indonesia, Somalia and parts of Central Asia are outside the Window. And, unfortunately, there have been a number of anecdotal stories (I have not tracked down the truth of them) about churches that say ‘we only fund work inside the 10/40 Window.’ There are several immediate side effects. First, a sudden redistribution of resources can leave people working ‘outside’ the Window in a bit of a lurch. Further, in our rapidly globalizing world, prioritizing on 'the 10/40 Window' can sometimes be difficult to decipher. For example, take my own work. I am headquartered in Dallas. My work involves advocacy for the unreached--but am I working ‘inside’ or ‘outside’ of the Window? Or, consider a worker who labors on behalf of a Window-country where they cannot live full-time—like Syria, Iran, Yemen, Somalia--are they 'inside' our 'outside'? Second, a fixed focus on the 10/40 Window it can make people who are working with non-Window yet ‘needy’ areas feel like second-class citizens. The reality we covered before: something like 90% of Christian ministry spending is spent on existing church members. About 10% is spent on non-Christians. So while those who have yet to hear the Gospel once need vastly more resources directed at them, those who have yet to hear the Gospel twice need only slightly less (while the average church member might hear the Gospel 100 times a year!). Some people do need to hear the Gospel more than once. Third, obviously the trends of globalization, diasporas, and people-on-the-move disturbs the whole 10/40 Window idea: you will find ‘Window’ peoples outside the Window far more than ever before. A colleague told me how the mother of an Iranian friend recently came to follow Jesus while visiting her daughter. Through the influence of the mother and the daughter, the Gospel has reached the daughter’s sister. It’s not an absolute rule, but the Gospel found in one place can flow across family lines back into the Window. Investing in a worker who lives outside the Window can be very strategic. What’s the answer? Should we abandon the Window? Not necessarily. Here are some practical things to perhaps keep in mind: 1. The Window is a valuable tool. It’s an easy way to refer to a region of the world where the majority of the unreached live. When you say ‘10/40 Window’ or ‘unreached’ most of those with an inkling of mission vision know what you’re talking about. It is important to keep these regions of the world ‘in view.’ 2. The Window is not a rule. Making a specific geographic location the ‘only’ place we will work is not wise. We need to think about how we will get the Gospel inside the Window, while recognizing the fuzzy nature of its boundaries, and realizing sometimes the best way to work inside the Window is to put ourselves outside it. 3. There are valid ministry callings outside the Window. If God calls you to Italy, go to Italy. If someone has a calling to a non-Window place, try to help them in the calling, even if your church, as a rule, doesn’t financially support those areas. Prayer, encouragement, advice and connections can all be just as important as money. 4. There are people from the Window around those of us outside the Window. If we look carefully, we’ll likely find some diaspora people very nearby. (I have seen them in some of the most seemingly unlikely places throughout rural mid-West America.) Just because you’re not ‘inside’ the Window doesn’t mean you can’t have an impact on it. It’s true that, technically, the term ‘unreached’ (or ‘unevangelized,’ or ‘World A’) can perhaps meet some (but not all) of these weaknesses, but I have often found that ‘unreached’ and ‘10/40 Window’ are used interchangeably: both to refer to a specific geographic area. And ‘unreached’ has strengths and weaknesses of its own. There’s no single perfect term. The main thing is to use these terms as tools, not to forge them into iron policies. They can be maps and guides to get to certain places, but you need to use other methods (prayer, wise counsel, etc.) to decide which places you will be investing in.