Aphrahat, also known as the Persian Sage, is one of the earliest authors of the Syriac tradition. His only extant writings, a series of twenty-three “Demonstrations” on various aspects of faith, provide a unique window into the practice of Christianity to the East of the Roman Empire in the early fourth century. Although he is a near contemporary with Ephrem, Aphrahat’s writings testify to a distinct practice of Syriac Christianity because of his geographic location in the Persian Empire. The Demonstrations provide many interesting observations about the practices and exegesis of Christians in the East. The present work is the first English translation of Aphrahat’s Demonstrations, carried out by Kuriakose Valavanolickal. Valavanolickal also includes an introduction to the life and writings of Aphrahat and a bibliography for further research. Volume I contains the Demonstrations on Faith, Charity, Fasting, Prayer, Wars, the Sons of the Covenant, Penitents, the Resurrection of the Dead, Humility, and Pastors.