What is the Trinity? Sproul covers “acres” of theological ground in 63 pages. His explanation for the Trinity is rooted in a discussion of monotheism: “The idea that there is one God was firmly established in the religion of Israel from the earliest pages of the Old Testament.” While the doctrine of the Trinity it not explicitly taught in the Old Testament, the strong teaching of monotheism is a crucial starting point.
Sproul continues by demonstrating how Scripture reveals the Trinity in the New Testament. The Father is distinguished from the Son and the Son is distinguished from the Holy Spirit. Yet we learned that he member of the Trinity is God. And when the Bible affirms the deity of the Father, Son, and Spirit, the Trinitarian formulation becomes clear.
The author provides a helpful section that concerns the Christological controversies of the 4th, 5th, 19th, and 20th centuries. The heresies and the key proponents are articulated and roundly refuted.
The author, in what may be the most helpful chapter of the book vividly distinguishes between “essence” and “person.” God is one in essence yet reveals himself in three persons, Father, Son, and Spirit: “The distinctions within the Godhead are, if you will, sub-distinctions within the essence of God. He is one essence, three subsistencies.” Sproul demonstrates how the doctrine of the Trinity is not only biblical but never violates the laws of logic. This is where Dr. Sproul is at his best: explaining theological truth and bolstering biblical reality with good philosophical foundations.
This work is short but packs a powerful punch. What is the Trinity? is an introductory resource that Christians need to read.