There are just four countries that are less than 0.1% Christian. These are the “least Christian” populations in the world, but altogether they represent just 133 million people. Another 24 countries are between 0.1% and 2% Christian, with 842 million people. These two blocks can be “generally” thought of as the core of the unevangelized or unreached (remember, these two concepts are not precisely the same). Together, they have 975.9 million people, most of whom by definition will no access to the Gospel in their lifetimes.
On the other side of the scale, there are 65 countries that are more than 90% Christian (of any tradition), with a grand total of 754 million people. (Obviously, some large portion of these are likely ‘cultural’ or ‘nominal’ Christians.) There an additional 104 countries that are between 32% and 90% Christian, with a total population of 2.39 billion people. Most of the world’s Christians live in these 169 countries.
This leaves 34 countries “in the middle”—between 2% and 32% Christian—where the vast majority of the world’s people (4.4 billion) actually live (India and China are both in this group, and represent over half this population). They have moderate access to the Gospel, but ‘inside’ these countries continue to be large gaps. Fortunately this means rapidly-multiplying movements originating from near-culture believers have a strong chance of reaching lots of unreached people, and from those initial steps finding bridges into the ‘unreached’ world which would—up until those people are reached—have been invisible. In other words, ‘routes’ into the least-Christian places of the world may be inaccessible to those in the ‘more’ Christian world, yet may be very open to those in the middle.
Strategically, most agencies (and missionaries) must ask which of these ‘bands’ they want to operate in: the 29 ‘least-Christian’ (red/orange on the map below), the 34 ‘in the middle’ (yellow), or the 169 ‘more Christian’ (including the saturated and nominal Christian countries) (blue). Each of these bands represent very different callings and strategies, all necessary in the long run.