The widely read author and philosopher Peter Kreeft presents a unique book that focuses on the important beliefs that Catholics and Protestants share in common. He says this book is inspired by Christ's high priestly prayer in the Gospel of John "that they may be one," and by St. John Paul II's ecumenical encyclical, Ut Unum Sint, which is also based on Christ's prayer for unity. While there are still significant differences, Kreeft says that there has been a radical step of agreement on the single most important issue, justification.
Kreeft says the style of the book is that of Pascal, Nietzsche, Solomon, and Jesus: short answers, single points to ponder rather than long strings of argument. It is direct, simple, and confrontational, but vertically rather than horizontally, "directing arrows not against each other (Protestant or Catholic) but against our own hearts and minds and wills."
It is timely because, as Pope St. John Paul II said, this next millennium is destined to be the millennium of Christian reunification as the first millennium was that of Christian unity, and the second one of Christian disunity.
Above all, Kreeft says that this work is simple, not easy, or obvious, but condensed. It – like all of reality – is Christocentric. Its purpose is to be "like an Australian sheep dog, herding and hectoring Christ's separated sheep back to His face. For that is the only way they can ever return back to each other."