And this is exactly where orthodox Christianity differs with LDS...biblical Christianity teaches that Elohim and YHWH (Jehovah is a non-word)are one in the same - two of many names for God. They are not two different Persons.
There are even times when God is called YHWH Elohim.
I believe that the bible does teach that they are two separate persons, yet one in unity, thought and purpose. An earthly shadow, a parallel, would be an ideally married couple. They share a common name. They share the same goals. They build toward these goals together. They are separate persons, yet one. "Elohim" could be considered the last name of God, while YHWH (an English representation of the Hebrew term) could be considered the personal name of Christ.
Christ seems to make this distinction in scripture:
Joh 1:18 No man hath seen God at any time; the only begotten Son, which is in the bosom of the Father, he hath declared him.
This is an amazing statement in that Christ says that nobody has seen the father. He states this in stronger terms later:
Joh 5:37 And the Father himself, which hath sent me, hath borne witness of me. Ye have neither heard his voice at any time, nor seen his shape.
Well we know that some Israelites DID hear a voice of God and did see his shape. They heard the voice of God at Horeb: Deu 1:6 The LORD our God spoke unto us in Horeb, saying, Ye have dwelt long enough in this mount:
So the only conclusion that can be drawn is as Restornu said, that the "God" who interacted with his people throughout the eons was the pre-incarnate Christ. And though he was "God", he is still separate and distinct from God the father.
Yet at the same time, he makes it clear that he exactly represents God, the father:
Joh 14:7 If ye had known me, ye should have known my Father also: and from henceforth ye know him, and have seen him.
Joh 14:8 Philip saith unto him, Lord, show us the Father, and it sufficeth us.
Joh 14:9 Jesus saith unto him, Have I been so long time with you, and yet hast thou not known me, Philip? he that hath seen me hath seen the Father; and how sayest thou then, Show us the Father?
Joh 14:10 Believest thou not that I am in the Father, and the Father in me? the words that I speak unto you I speak not of myself: but the Father that dwelleth in me, he doeth the works.