If the unchurched in the United States ever formed their own country, it would be the world's eleventh most populous nation. Reformission is a call to reform a flawed view of missions--as something we only do in foreign lands--to focus on the urgent needs in our own neighborhoods, filled with diverse Americans who desperately need the Gospel of Jesus and life in his Church. It calls for a movement of missionaries who seek the lost across the street, as well as across the globe.

Many evangelical churches today are either hostile to the unbelieving world in which...