The book "Rational Religiosity" by Peter Kleinert offers an in-depth exploration of the fundamental questions of existence and spirituality in a world often marked by nihilism. Kleinert argues that the mechanistic-materialistic worldview is challenged by the insights of quantum physics. He draws parallels between the Neoplatonic doctrine of the ancient philosopher Plotinus and modern scientific approaches. These comparisons open up new perspectives on the philosophy of religion and demonstrate that a spiritual awakening in conjunction with rational thinking is possible. By revisiting Plotinus' legacy, his arguments are viewed in a new light, leading to a compelling and relevant discussion about faith and science.