Who was Fr. Sergius Bulgakov, the pastor who stands behind the epochal theology of Eastern Orthodox sophiology? What better place to look than his own Spiritual Diary, which opens to us the mind and heart of this prolific and original theologian of the twentieth century? This volume, the first of his diaries to be published in English, depicts in illuminating detail Bulgakov's daily life as a priest ministering in exile, the exultations and desolations of his personal prayer life, and his confoundment and pain towards the fate of his homeland ruled by the aggressively atheist Soviet state. In these personal reflections we discover the pastoral matrix from which arose such distinctive features of Bulgakov's mature theology as his theology of Sophia, the Divine Wisdom, as God's mystical presence in creation. Beyond this, however, at its core the Diary is a work of spiritual edification and meditation meant to draw the reader into contemplation. Together with biographical and theological introductions provided by the translators, this volume will serve scholars of Bulgakov and Orthodox theology as well as Christians of all traditions who wish to unite their theology with prayer.