The Catholic Church has called for a “new evangelization” of the de-Christianized world. Pope Francis has frequently called for Catholics to be missionary disciples, bringing the love of Christ to those who do not know him. Yet, Catholics seem to have confusion about, or even a lack of interest in, the church’s leaders’ repeated encouragement of mission. Why is this? This book alleges that the problem lies largely with the experts in mission themselves, who seem to relativize or minimize the church’s essential task of calling all peoples to belief in Christ and baptism into his church. If the church forgets what her essential task is, then her purpose becomes unclear and her work becomes useless. This book is a contribution towards calling the church back to this essential task.