Many Christians like to make a big deal about the word Elohim in Genesis 1. Elohim is the plural for "god," yet, in Genesis 1, it occurs with singular verbs. For a lot of Christians, this means the Old Testament views "God" as a collective.
A lot of Christians believe this is evidence for the trinity. "When a Jewish person or a Jehovah's Witness disputes the trinity, you should point him to Genesis 1," Christian apologists boldly claim. "Elohim is plural, yet the verb is singular. God is three persons, but he is still one God."
Armstrongites, however, do not see God as a trinity, since they don't think that the Holy Spirit is God. So how do they approach the verse? They say that Elohim can mean a binity: two persons (the Father and Jesus) in one God family (which will expand to include more members once believers become divine). After all, Elohim is plural, and all you need is more than one person to have a plural, right? So Elohim can mean that God is a binity, as far as Armstrongites are concerned.
"Not so fast," respond trinitarians. On Felix's post a while back, Guess What I found on Youtube.com???, there is a debate between John Ankerberg and the late Garner Ted Armstrong over the trinity. Someone from Ankerberg's audience attempts to discredit Armstrong's binitarian interpretation of Genesis 1 through an appeal to Gesenius' Hebrew Grammar. Essentially, he argues that the Hebrew uses the dual whenever it discusses two of something, but it employs the plural for more than two. According to this reasoning, had Genesis 1 wanted to convey that the Godhead has two members, it would have used the dual Elohayim, not the plural Elohim. But it uses the plural Elohim, so it must be saying that God is more than two persons. Therefore, the trinity wins, right?
In my humble opinion, they're all wrong. If one reads the Hebrew Bible on its own terms rather than forcing it into the mold of orthodox or Amrstongite Christianity, one will see that it also uses the plural for "god" with a singular verb when it discusses non-Israelite deities. But it's only talking about one deity when it does so. For example, take Judges 16:23-24, noting in particular the parts in red:
The lords of the Philistines assembled to offer a great sacrifice to their god Dagon and to make merry. They said, "Our god has delivered into our power Samson our enemy." When the people saw him, they praised their god. For they said, "Our god has delivered into our power our enemy, the ravager of our land, the one who has multiplied our slain." Then they stationed him between the columns. (NRSV, emphasis mine)
The word for "our god" is "elohenu," which is plural. And the word for "has delivered" is "natan," which is singular. Grammatically speaking, Judges 16:23-24 refers to Dagon the same way that Genesis 1 speaks of the Israelite God: plural subject, singular verb. Yet, Judges 16:23-24 is not saying that Dagon is a trinity, or a binity, or a family, or even collective. There's only one Dagon! So the use of the plural for "God" in Genesis 1 is fully consistent with strict Israelite monotheism.
So why does the Hebrew do this for gods? A professor at DePauw once told me that the Israelites couldn't conceive of putting "God" in the singular, since they thought he was so glorious and majestic. So maybe we see the plural of majesty here. I don't know.
But I will say this: Even if the trinity is true, appealing to the use of Elohim in Genesis 1 to support it is problematic.