One and Three: The Monotheistic Doctrine of the Trinity

Christianity, Judaism, and Islam stand as the three major monotheistic faiths in world religion. They are not the only three—other monotheistic faiths include Sikhism, Zoroastrianism, and the Bahai Faith—but they are the largest, and they share a common thread in that each claims to worship the God Abraham.

Christianity, however, is distinct among the three for its trinitarian formulation. Only in Christian theology does God exist as one God in three persons: Father, Son, and Holy Spirit.

While critics of Christianity have long asserted that the Trinity is alien to Scripture, and honest interrogation of the biblical text reveals that the roots of trinitarian truth are deeply embedded in the very soil of biblical revelation. A striking example is Paul’s words to the Corinthians, recorded in 1 Corinthians 8:4–6.

Addressing the very practical issue of food offered to idols, which threatened to divide the Corinthian church, Paul reaches back to the foundational confession of Israel’s faith to show that the identity of the one true God is richer and more profound than the Corinthians perhaps realised. The doctrine of the Trinity, far from undermining biblical monotheism, is its fullest expression.

At the heart of Israel’s faith stood a profoundly simple declaration. This truth, which set Judaism apart from polytheistic paganism, is found in Deuteronomy 6:4, where we read, “Hear, O Israel: The LORD our God, the LORD is one.” This statement—known as the Shema—was not a merely theological proposition. It was a confession of allegiance to the one true and living God, who alone is worthy of worship.

Surrounding nations worshipped a plethora of gods—deities of fertility, war, harvest, and weather—while Israel confessed one true God, who is Creator, sovereign, and who alone possesses true deity.

Paul affirms this as Christian truth in v. 4: “There is no God but one.” Christianity did not abandon the monotheistic tradition of the Old Testament; it stood firmly within it. The God of Abraham, Isaac, and Jacob was the one true God of Christianity.

Monotheism was not popular in Corinthian culture. Corinth was a city overflowing with temples and idols, each with a competing claim to spiritual authority. Paul acknowledges this reality in v. 5: “There are many ‘gods’ and many ‘lords’.”

These gods and lords were not incidental to daily life. They shaped trade, family, entertainment, social gatherings, and civic identity, which were all bound up with religious practice. To live in Corinth was to face consistent claims to competing allegiance.

Paul does not deny the existence of these claims, but he does expose their emptiness. These are, in fact, “so-called” gods (v. 5). They may be named, feared, and worshipped, but they possess no true deity. Unlike the true God, they have “no real existence” (v. 4).

This distinction is crucial. False gods may be culturally powerful, emotionally significant, and spiritually dangerous, but they are not God. Only one being possesses true deity.

It is at this point that Paul makes a profound theological shift. In v. 6, he writes: “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.”

At first glance, this may appear to be a departure from the Shema, with Paul introducing Jesus as a second Lord alongside the God of Abraham. In fact, it is a rearticulation of the Shema, couched in distinctly Christian terms.

Paul takes the language of “one God” and “one Lord,” deeply rooted in Deuteronomy 6:4, and applies it in a way that includes both Father and Son. He preserves divine unity, but adds clarity as to the nature of that unity.

This is the beginning of a fully trinitarian understanding of God.

Paul first identifies “one God, the Father.” This is consistent with the Old Testament. God the Father is the source of all things: “from whom are all things.”

Everything that exists finds its origin in him. Creation is not random or self-generating. It flows from the Father’s will and power. Moreover, Paul adds, “we exist for him.” The Father is not only the source, but also the goal, of all things. All of life finds its purpose in him.

Paul then speaks of “one Lord, Jesus Christ.” This is not a lesser title. The Old Testament acknowledges God as “Lord.” By applying this title to Jesus, Paul is not placing him alongside the Father as a lesser deity, but including him within the identity of the one true God.

This becomes even clearer when he adds, “through whom are all things.” Creation itself is attributed to Christ. He is not part of the created order; he is the one through whom all things came into being. This echoes the testimony of John 1:3: “All things were made through him, and without him was not any thing made that was made.”

This language can only be used of God. If all things are through Christ, then Christ must stand on the Creator side of the Creator–creature divide. He is not a created being. He is the eternal creator.

Paul’s words are so striking because, with them, he affirms two simultaneous truths: There is one God, and yet Father and Son are fully included within that one divine identity. This is not a contradiction. It is a revelation.

Within the unity of the divine being, there is a distinction of persons. The Father is not the Son, and the Son is not the Father. Yet each is truly and equally God. The doctrine of the Trinity arises from precisely this kind of biblical witness. It is not an abstract philosophical construction but a faithful summary of what Scripture reveals about God.

At first glance, this may seem like a discussion for theological pedants and ivory towers seminarians, far removed from everyday life. But for Paul, this truth has immediate and practical implications.

If there is one God, worship cannot be divided. If Jesus Christ is Lord, he cannot be treated as one loyalty among many. The confession of the Trinity is not merely about getting our doctrine right; it is about getting worship right.

In a world filled with “many gods and many lords”—whether in the form of stone statues, success, approval, comfort, or power—the Christian confession remains clear and exclusive: There is one God, the Father, and one Lord, Jesus Christ. This confession calls for undivided allegiance. It demands that we turn away from every rival and give ourselves wholly to the living God.

The doctrine of the Trinity is not an abstract puzzle to be solved but a truth to be believed, confessed, and lived. It tells us who God is, and therefore how we are to respond. We are not free to invent our own understanding of God. We receive him as he has revealed himself: one God, eternally existing as Father, Son, and Holy Spirit.

And as we grow in our understanding of this truth, we are drawn into deeper worship, for the God we confess is not distant or impersonal, but the living God who creates, redeems, and calls us to himself.

To confess the Trinity, then, is to stand within the great stream of biblical revelation. It is to affirm with Israel that the Lord is one, and to rejoice with the apostles that this one God has made himself known in the person of Jesus Christ, the eternal Son. And it is to bow in worship, acknowledging that he alone is worthy of all glory, honour, and praise.