This book is a systematic commentary on the Apocalypse of Saint John, examining each chapter and verse based on the original Greek and Latin texts. The underlying hermeneutic is an idealist or allegorical point of view that does not attempt to identify apocalyptic imagery with concrete historical events. Rather, symbols and metaphors are interpreted, with attention to their intertextuality, as paradigmatic of the epic battle between the forces of light and darkness, good and evil, the dragon and the Lamb, playing out not only in the vicissitudes of the world today, but also and especially in one’s personal life. Rather than focusing on sterile symbolisms, the book attempts to inspire a more radical discipleship of Jesus by applying the eschatological imagery to the realm of spiritual discernment. John’s Apocalypse is certainly considered the grand New Testament Theology of History, but here its ethical dualism is mainly taken as a challenge for the interior life, to enter into the worship before the throne of Christ the Lamb, and to realize that where evil makes war against the principles of good, God will remain in control at all times. The author has drawn on two commentators whose work has not been translated and made widely accessible until now, Rupert of Deutz and Adrienne von Speyr. The book aims to relay Revelation’s message of Christ-centered faithfulness and perseverance, of virtue and holiness, once addressed to the seven churches in Asia, to a contemporary readership.