The other unreached people group

The 10/30 Window will be the one to watch in 2012 | Mindy Belz

Photo by Roberto Schmidt/AFP/Getty Images

Most of us know the 10/40 Window, that geographic band between 10 and 40 degrees north latitude that's home to the largest unreached people groups—and the poorest and most spiritually impoverished—in the world. Its billion account for the majority of the world's Muslims, Hindus, and Buddhists.

Fewer of us have heard of the 10/30 Window, and I'm grateful for a recent orientation session from two experts, Eric Larsen and Jonathan Taylor of Global Youth and Family Ministries. They believe missions are both geographic and generational, and they have dubbed the 2.4 billion of the world's population between the ages of 10 and 30 as the 10/30 Window. Taylor told me these youth constitute "the largest unreached people group in human history, larger than the 100 largest geographically defined unreached people groups combined."