Genesis 1:26 says, “Then God said, ‘Let us make man in our image, in our likeness, and let them rule over the fish of the sea and the birds of the air, over the livestock, over all the earth, and over all the creatures that move along the ground.’” Genesis 3:22 states, “And the LORD God said, ‘The man has now become like one of us.’” There are other passages in the Old Testament in which God refers to Himself using plural constructions. It is also interesting to note that Elohim, one of the primary titles of God in the Old Testament (occurring over 2,500 times), is in the plural form.
Some people have used these verses to hypothesize that there are more than one God. However, we can rule out polytheism (belief in multiple gods), because that would contradict countless other Scriptures that tell us that God is one and that there is only one God. Three times in Isaiah 45 alone, God states, “I am the LORD, and there is no other; there is no God besides Me” (vv. 5, 6, 18).
A second possible explanation for God’s referring to Himself in the plural is that God was including the angels in His statement. In saying “us” and “our,” God was speaking of all the heavenly host, Himself included. However, the Bible nowhere states that angels have the same “image” or “likeness” as God (see Genesis 1:26). That description is given to humanity alone.
Since the Bible, and the New Testament especially, presents God as a Trinity (three Persons but only one God), Genesis 1:26 and 3:22 can only represent a conversation within the Trinity. God the Father is having a “conversation” with God the Son and God the Holy Spirit. The Old Testament hints at the plurality of God, and the New Testament clarifies this plurality with the doctrine of the Trinity. Obviously, there is no way we can fully understand how this works, but God has given us enough information to know that He does exist in three Persons—Father, Son, and Holy Spirit.