Where in the Bible does it say there is only one God?

The Bible emphatically and repeatedly declares the existence of only one God, a foundational tenet of monotheism that is central to the Christian faith. This belief is not merely an abstract doctrine but is woven into the very fabric of biblical revelation, shaping the understanding of God's nature and the relationship between God and humanity. To fully appreciate the biblical assertion of monotheism, we must explore a variety of scriptural passages that affirm this truth.

One of the clearest declarations of monotheism in the Old Testament is found in the Shema, a traditional Jewish prayer that is recited daily. Deuteronomy 6:4 states, "Hear, O Israel: The Lord our God, the Lord is one." This verse not only affirms the oneness of God but also serves as a call to exclusive devotion. The Shema emphasizes that the God of Israel is unique and singular, thereby rejecting the polytheistic beliefs that were prevalent in the ancient Near East.

The prophet Isaiah also provides profound insights into the nature of God, particularly in his polemic against idolatry and false gods. Isaiah 44:6 declares, "Thus says the Lord, the King of Israel and his Redeemer, the Lord of hosts: 'I am the first and I am the last; besides me there is no god.'" This passage underscores God's eternal existence and singularity, affirming that there is no other deity beside Him. Similarly, Isaiah 45:5-6 proclaims, "I am the Lord, and there is no other, besides me there is no God; I equip you, though you do not know me, that people may know, from the rising of the sun and from the west, that there is none besides me; I am the Lord, and there is no other."

Moving to the New Testament, the monotheistic conviction remains steadfast. Jesus Himself reiterates the importance of the Shema in Mark 12:29 when He responds to a scribe's question about the greatest commandment: "Jesus answered, 'The most important is, 'Hear, O Israel: The Lord our God, the Lord is one.'" Here, Jesus affirms the continuity of the monotheistic faith from the Old Testament to the New Testament, emphasizing that the foundational belief in one God remains unchanged.

The Apostle Paul also contributes significantly to the New Testament's affirmation of monotheism. In 1 Corinthians 8:4-6, Paul addresses the issue of food offered to idols and underscores the uniqueness of the Christian God: "Therefore, as to the eating of food offered to idols, we know that 'an idol has no real existence,' and that 'there is no God but one.' For although there may be so-called gods in heaven or on earth—as indeed there are many 'gods' and many 'lords'—yet for us there is one God, the Father, from whom are all things and for whom we exist, and one Lord, Jesus Christ, through whom are all things and through whom we exist." Paul acknowledges the existence of many so-called gods and lords but unequivocally affirms that for Christians, there is only one God, the Father, and one Lord, Jesus Christ.

Another significant passage is found in 1 Timothy 2:5, where Paul writes, "For there is one God, and there is one mediator between God and men, the man Christ Jesus." This verse not only reaffirms the belief in one God but also highlights the unique mediatory role of Jesus Christ, reinforcing the Christian understanding of the relationship between God, humanity, and salvation.

James, the brother of Jesus, also echoes this monotheistic belief in his epistle. James 2:19 states, "You believe that God is one; you do well. Even the demons believe—and shudder!" Here, James emphasizes that belief in one God is foundational, but he also challenges his readers to recognize that mere intellectual assent is insufficient without corresponding action.

The Book of Revelation, with its rich and symbolic imagery, also affirms the oneness of God. In Revelation 4:11, the heavenly beings worship God, saying, "Worthy are you, our Lord and God, to receive glory and honor and power, for you created all things, and by your will they existed and were created." This doxology acknowledges God as the sole creator and sustainer of all things, reinforcing the monotheistic belief.

Throughout the Bible, the consistent message is clear: there is only one God. This foundational belief shapes the entire biblical narrative and has profound implications for theology, worship, and ethical living. The monotheistic faith of the Bible stands in stark contrast to the polytheistic religions of the ancient world and continues to distinguish Christianity in the contemporary religious landscape.

In addition to the biblical texts, early Christian creeds and confessions also affirm this monotheistic belief. The Nicene Creed, formulated in the fourth century, begins with the declaration, "We believe in one God, the Father Almighty, Maker of heaven and earth, and of all things visible and invisible." This creed, which remains a central statement of faith for many Christian denominations, encapsulates the biblical teaching of one God and underscores its enduring significance.

The belief in one God also has practical implications for how Christians live out their faith. It calls for exclusive devotion and loyalty to God, rejecting any form of idolatry or divided allegiance. It shapes the understanding of God's nature as the ultimate source of all truth, goodness, and beauty, and it informs the ethical and moral decisions that believers make in their daily lives.

Moreover, the doctrine of the Trinity, while affirming the oneness of God, also reveals the complexity and depth of the divine nature. The Christian understanding of one God in three persons—Father, Son, and Holy Spirit—maintains the unity of God while also acknowledging the distinctiveness of each person of the Trinity. This theological insight enriches the monotheistic belief, providing a more profound understanding of God's relational and dynamic nature.

In conclusion, the Bible unequivocally teaches that there is only one God. This belief is foundational to the Christian faith and is consistently affirmed throughout both the Old and New Testaments. From the Shema in Deuteronomy to the teachings of Jesus and the writings of Paul, the biblical witness to monotheism is clear and compelling. This doctrine not only shapes the theological framework of Christianity but also has profound implications for worship, ethics, and the lived experience of faith.