Book excerpt: Oliver B. Langworthy examines the interaction of soteriology and pneumatology in Gregory of Nazianzus' thought. He shows that this interaction, Gregory's soteriological pneumatology, is a coherent, significant, but under-examined area of Gregory's thought. His study engages in a chronological treatment of a wide range of Gregory's prose and poetic works. This allows for the particular character of Gregory's soteriological pneumatology to emerge, notably his emphasis on the experience of the Spirit. The result is a more complete and nuanced picture of Gregory's theological investment in a divine and "truly holy" Spirit that is operative in the salvation of the believer.