Readers of the Old Testament have thought of different explanations for why God is referred to in the Old Testament by different names. I mean, he's referred to as Yahweh; he's referred to as Elohim, which means God; and he's referred to as El, another word for God. Historical critical scholars in the last few hundred years have especially focused on these different names as a way to piece apart what they speculate are different sources, different source documents that have been brought into the Pentateuch, and that especially before the revelation of the name of Yahweh in Exodus 3, you could always tell as you're reading along whether a particular part of the narrative, even a particular phrase as you go through the document, is from the Yawist document or the Eloist document based on what name they're using for God. So, that's one explanation, is that there are different sources behind the Pentateuch that use different names for God. I think that that's really kind of an unnatural explanation and that it makes perfect sense that God would be referred to by different names as the narrative goes along, just as we refer to God by different names in our day. We refer to him as Lord, and Father, and God, Jesus, Yahweh, Jehovah. But why? Why in a given passage would he be called one name and in another passage another? Well, there's a long tradition that there is really kind of a different accent to the name Yahweh than to the name Elohim or El within the narrative, that the name Yahweh is the familiar covenant name of God, the fulfiller of his promises to his people. It's the intimate name that's used of God in context, especially where he is the covenant God of Israel; whereas Elohim, God, is a more cosmic name, a more transcendent name. It pictures God in his majestic rule over all the nations and over all the peoples.

And I think that that difference, that explanation, can be helpful and does seem to apply in some places. But I also think that it's helpful to remember that these different names from God are different kinds of words, that they aren't just equivalent names for God, but that one of them is a personal name. Yahweh is a name like my first name is Tom. God's first name, his given personal name, is Yahweh. The name Elohim is technically not a name but a title. It means "God." It refers to his divinity, and also the name El. So that, in usage in the Old Testament, there would be times when it would be appropriate to use one rather than another. For example, if I want to say "your God" I would not use the word Yahweh with a descriptor your. We don't say "your Yahweh." We say "your God." If I wanted to use an adjective– In Hebrew, they like to use the divine name El when they use an adjective, so if you say, "a gracious and compassionate God," you would use El rather than Elohim or Yahweh. So, there are just some grammatical rules that govern the usage of the names as well.