“Is there a book that might capture the story of the twentieth century? ... Perhaps there is a book one could select and about which one could say, Here is the story. It is not a narrative, nor a work of theology, but a book of statistics: Operation World, begun by Patrick Johnstone. At first glance, it might seem intensely boring. But its superabundance of statistics tells us that throughout the world there are millions of boys and girls, young people, men and women, some of them in the most unlikely places, some facing enormous personal pressure and persecution, who follow Jesus Christ and are the living proof of His promise, I will build my church; and the gates of hell shall not prevail against it.”

“For years I have used Operation World to pray for people in every tongue, tribe and nation. Operation World is a time-honored and well-tested global manual of prayer that will provide you with everything you need to bring the nations of the world before the throne of God. It will expand your heart, vision and passion for the peoples of the world and God's deep desire to reach those in the darkest corners with his help and hope.”

“Outside of the Bible, no book has had a greater practical impact on my personal prayer life than Operation World. God has used this book to open my eyes and the eyes of the church I pastor to the needs of the world and the greatness of the God who desires to make his glory known in the world. I eagerly welcome this new edition and wholeheartedly recommend it.”

“"In the world of missions, I know of nothing more significant than Operation World, when it comes to learning about the need, opportunity and prayer points for world evangelism.”

“A veritable source of mission information about the status of the remaining task and a tool that brings together in one volume detailed update that inspires passion for the unreached and stirs up hearts to intercede.”

“An invaluable source of background information on every country we work in . . . . It has provided an objective platform of information that combines well with our own experiential perceptions in the task of strategic planning.”

“This is probably one of the most important missionary tools in the entire history of missions.”

“The scope and thoroughness of the research done by Jason Mandryk and his colleagues is truly commendable.”

“A tremendously useful resource that I use personally, with my family and in my ministry.”