There is a lot of talk among Christians today about harvest. Churches, Bible schools and Christian ministries use the term in their programs, advertisements, mottoes, even their corporate names, to pique their members’ concern for reaching the lost. The term is a biblical one. Jesus used it in His teachings to call His disciples to prayer and action. Harvest, in the biblical use of the word, is certainly about the lost. But, does the Bible say anything more specifically about this harvest? In agricultural communities, harvest time is the season when crops, which are now ripe, must be brought in. Every farmer understands that harvest is about readiness, potential and urgency. The crops are ready, there is great potential for profit (or loss), and urgent action is necessary to gather and preserve the yield. Jesus said, “The field is the world.” In missionary terms, is it possible that some parts of this field are ready to be brought in now while others are not? At any given time in history, are some people more receptive to the Savior than others? The answer is an obvious yes! We understand how receptivity applies to individuals, but the same is true for entire people groups! This book explores how today’s Christian missionary can find receptive people groups and work fruitfully among them. It also suggests how to minister to indifferent and unreceptive people, and provides a model for evaluating Christian missionary work in light of receptivity principles.