In particular, I want to focus on one specific issue: Who spoke to Moses in the burning bush?
Your initial answer might be "God"--but let's look at this a little more carefully.
Exod 3:2-6:  And the angel [Heb. mal’ak ="messenger"] of the LORD appeared to him in a flame of fire out of the midst of a bush; and he looked, and lo, the bush was burning, yet it was not consumed.  And Moses said, "I will turn aside and see this great sight, why the bush is not burnt."  When the LORD saw that he turned aside to see, God called to him out of the bush, "Moses, Moses!" And he said, "Here am I."  Then he said, "Do not come near; put off your shoes from your feet, for the place on which you are standing is holy ground."  And he said, "I am the God of your father, the God of Abraham, the God of Isaac, and the God of Jacob." And Moses hid his face, for he was afraid to look at God.So who spoke to Moses, the angel or the Lord, Yahweh? Recall that YHWH literally means, "I AM". Is this the messenger of God or the great "I AM" himself?
Well, first, it is important to note that the word translated angel is mal’ak, which simply means "messenger". It often does denote angelic creatures--angels--since they are often the "messengers" of God in the Old Testament. But the word need not necessarily refer to that genus of species. In fact, it is odd that the angel is somehow both the messenger and the Lord Himself... unless, of course, you're a Christian.
In the New Testament, Jesus is described as the "one sent" by God--the Messenger or Apostle of God. In John 6:29 Jesus states: “This is the work of God, that you believe in him whom he has sent.” Here Jesus clearly identifies Himself as the one "sent" by God.
Something similar is found in Hebrews 3:1: "Therefore, holy brethren, who share in a heavenly call, consider Jesus, the apostle and high priest of our confession."
In fact, in John 8 Jesus makes a stunning claim. We'll join the story already in progress...
John 8:56-59:  Your father Abraham rejoiced that he was to see my day; heThe crowd picks up stones to stone Jesus because they recognize what he has just done--he has claimed to be "I AM"--the Lord himself.
saw it and was glad."  The Jews then said to him, "You are not yet fifty years old, and have you seen Abraham?"  Jesus said to them, "Truly, truly, I say to you, before Abraham was, I am."  So they took up stones to throw at him; but Jesus hid himself, and went out of the temple.
In other words, Jesus turns to the crowd on this day and says, "Remember that day Moses spoke to the angel/God in the burning bush? ... That was me--nice to meet you."
Well--that's a paraphrase.
Anyway, this is how the earliest Christians understood this text. The following is from Justin Martyr:
"Now the Word of God is His Son, as we have before said. And He is called Angel and Apostle; for He declares whatever we ought to know, and is sent forth to declare whatever is revealed; as our Lord Himself says, "He that heareth Me, heareth Him that sent Me." From the writings of Moses also this will be manifest; for thus it is written in them, "And the Angel of God spoke to Moses, in a flame of fire out of the bush, and said, I am that I am, the God of Abraham, the God of Isaac, the God of Jacob, the God of thy fathers… But so much is written for the sake of proving that Jesus the Christ is the Son of God and His Apostle, being of old the Word, and appearing sometimes in the form of fire, and sometimes in the likeness of angels; but now, by the will of God, having become man for the human race, He endured all the sufferings which the devils instigated the senseless Jews to inflict upon Him; who, though they have it expressly affirmed in the writings of Moses, "And the angel of God spoke to Moses in a flame of fire in a bush, and said, I am that I am, the God of Abraham, and the God of Isaac, and the God of Jacob," yet maintain that He who said this was the Father and Creator of the universe” (First Apology, LXIII).