The book "Passion for Nothing: Kierkegaard’s Apophatic Theology" by Peter Kline explores the concept of nothingness in the works of Kierkegaard and Meister Eckhart. Kline argues that this idea of nothingness is central to Kierkegaard's negative theology, leading to a life of self-denial and deep spiritual searching. However, Kline's interpretation of nothingness as absolute indeterminacy may go too far, stripping Jesus of any identity or messianism. This challenges Kierkegaard's belief in Jesus as the Redeemer who takes on the sins of humanity. Ultimately, the book delves into the complex relationship between nothingness, self-denial, and the nature of Christ in Kierkegaard's philosophy.