This research paper by Joshua Duemler, submitted to Dr. D. Blair Smith for ST6100 – Trinitarian Theology at Reformed Theological Seminary – Charlotte, examines Isaiah 48:16 as an Old Testament revelation of the Trinity. Duemler argues that the verse presents a dialogue within the Godhead, where the Son speaks as the one sent by the Lord God and His Spirit, revealing an early scriptural pattern of Trinitarian relations.
Through detailed exegesis of the Hebrew text and analysis of early church, medieval, and Reformation interpretations, Duemler traces how theologians from Augustine to Aquinas and Owen used this verse to discuss the deity of the Holy Spirit and the mission of the Son. He highlights the development of two major interpretive threads: the affirmation of the Spirit’s divinity and the theological understanding of the Son’s being sent by both Father and Spirit.
The paper concludes that Isaiah 48:16 serves as a rich theological witness to the unity and distinction of the divine persons—Father, Son, and Spirit—demonstrating that the Old Testament, rightly read in the light of the New, proclaims the fullness of God’s triune nature.
Course and semester: ST6100 Trinitarian Theology — Spring 2021
