While most arguments for the Trinity are grounded in the New Testament, God begins revealing His triune nature in the Old Testament. One hint at the plurality and unity of the Godhead may be found in several passages where God speaks.
For example, Genesis 1:26 reads, “Then God said, ‘Let us make man in our image, according to our likeness.’” Here, the verb “said” is singular, but the verb “let us” is plural, as are the possessive endings of the nouns “our image” and “our likeness.” Then, in the next verse we read, “So God created man in his own image; he created him in the image of God; he created them male and female” (v. 27).
Genesis 3:22-24 provides a similar clue: “The LORD God said, ‘Since the man has become like one of us, knowing good and evil, he must not reach out, take from the tree of life, eat, and live forever.’ So the LORD God sent him away from the garden of Eden to work the ground from which he was taken. He drove the man out …”
Other examples include:
Genesis 11:7, where the LORD says, “Come, let’s go down there and confuse their languages so that they will not understand one another’s speech.” Then, in verses 8 and 9, the LORD “scattered them” and “confused the language of the whole earth.”
Isaiah 6:8 – “Then I heard the voice of the Lord asking: Who should I send? Who will go for us?”
Commentators provide a variety of explanations for these verses. Some contend that, in the Genesis passages, God is addressing a council of heavenly creatures entrusted with authority on earth. These creatures include cherubim, who we encounter in Genesis, Ezekiel, and elsewhere, as guardians of God’s holiness (Gen. 3:24; Exod. 36:35; 1 Kings 6:23-29; Ezek. 1:5-26; 10:1-22). In the Isaiah 6 passage, Yahweh may be speaking to a heavenly court that includes the seraphim, six-winged creatures that stand above God’s throne and declare His holiness (see verses 2-3, 6-7).
Others scholars assert that these texts show the Lord speaking to subordinates He used in the process of creation. Still others say Yahweh is employing the “plural of majesty” used of important people, like kings; its plural form does not necessarily designate any sort of plurality. And then, some ancient writings and commentaries simply alter or delete these passages.
While we should take note of these Old Testament texts, we don’t want to press the issue too strongly, since God’s self-revelation in Scripture is progressive. As we move through the Old Testament and into the New Testament, we see more clearly the revealed truth of one God in three persons.
We should note there are crucial differences in the ways the world’s three major monotheistic religions – Judaism, Islam, and Christianity – understand the reality of one God. Judaism holds strongly to the doctrine of one God and rejects the Christian doctrine of the Trinity. Yet, ancient Israelites taught that the Hebrew Bible bore witness to two Yahweh figures – “two powers” in heaven, one invisible and the other visible, the visible power being the Angel of the LORD.
Islam also denies the Trinity, embracing a monolithic oneness in its concept of God. The Muslim doctrine of tawhid declares that Allah is absolutely and singularly one. He takes no “partners.” That is, he acknowledges no other divine members of a godhead. He is not relational, which means human beings cannot be considered his sons and daughters. Allah reveals his will, not himself. To say that Jesus is the Son of God is to commit the sin of shirk, which may damn a soul to hell.
In contrast, the God of the Bible is triune: one being in three persons. Father, Son, and Holy Spirit are eternally loving and relational. Their attributes, such as love and mercy, are not contingent on creation, for these divine traits are eternal and unchanging. Further, Yahweh creates people with a God-like capacity for personality, selfless love, and relationships with one another and, more importantly, with their Creator.