Youssef worked for nearly 10 years with the Haggai Institute,[2] traveling around the world[3] and teaching courses in evangelism and church leadership to church leaders. He founded the Church of the Apostles in 1987, and has authored more than 35 books, including the popular titles "The Barbarians Are Here", "End Times and the Secret of the Mahdi," and "Jesus, Jihad and Peace."