As different as Christianity, Judaism, and Islam are, they do have one thing in common. Each affirms that there is only one God. Christians, however, believe that the one God exists in a unity of three persons: Father, Son, and Holy Spirit. In the eyes of Judaism and Islam, this belief amounts to polytheism. Christian theology does not teach that the members of the Trinity are three separate gods. Deuteronomy 6:4 affirms that “the LORD is one,” a statement repeatedly emphasized in the New Testament (Mark 12:29; Gal. 3:20; Eph. 4:6; James 2:19).
God is “one” in a numerical sense. There is only one true God, not many gods. God the Father, our Lord Jesus Christ, and His Holy Spirit is the only Creator and sustainer of all that exists (Gen. 1:1, Col. 1:16). He has no superior and does not have any equal. God is also one in the sense that He is one in all that He is and does. He is integrated in terms of His nature, plan, and actions.
Although the world’s religions recognize many gods, “yet for us there is but one God, the Father, from whom all things came and for whom we live; and there is but one Lord, Jesus Christ, through whom all things came and through whom we live” (1 Cor. 8:6). The triune God does not consist of three divine essences. Instead, the three Persons, although distinct, are one divine essence.
Why Theology Matters
The doctrine of divine unity is essential to the doctrine of the Trinity. Without it, Christianity would be a form of polytheism. It also underscores the uniqueness of the Christian faith. Many believe that since there is only one true God, all religions worship the same God. The biblical doctrine of unity reveals that the only true God is the Father of our Lord Jesus Christ. Those who do not acknowledge Christ as the divine Son of the Father do not worship the true God.
FOR FURTHER READING
For a better understanding of the uniqueness of the one God of the Bible, read Is the Father of Jesus the God of Muhammad? by Timothy George (Zondervan).