I’m surprised to hear that Mr. Camping thought the Angel of the LORD in these verses was an angelic being and not God Himself. Whenever we read about the Angel of the LORD in the Bible it is always referring to God Himself. Here are some examples that show this, Genesis 22:11-12:
And the angel of the LORD called unto him out of heaven, and said, Abraham, Abraham: and he said, Here am I. And he said, Lay not thine hand upon the lad, neither do thou any thing unto him: for now I know that thou fearest God, seeing thou hast not withheld thy son, thine only son from me.
Who is Abraham speaking with? It is the Angel of the LORD that called to him out of heaven. And yet, the very next verse (12) says “I know that thou fearest God, seeing thou hast not withheld thy son, thine only son from ME.” This is even clearer when the Angel of the LORD calls unto him a second time, Genesis 22:15-16:
And the angel of the LORD called unto Abraham out of heaven the second time, And said, By myself have I sworn, saith the LORD, for because thou hast done this thing, and hast not withheld thy son, thine only son:
The Angel of the LORD is calling Abraham, and without missing a beat it goes on to say that LORD Himself is the One speaking to Abraham. This can only be the case if the Angel of the LORD and LORD are One and the same. Exodus 3:2:
And the angel of the LORD appeared unto him in a flame of fire out of the midst of a bush: and he looked, and, behold, the bush burned with fire, and the bush was not consumed.
The Angel of the LORD appeared to Moses out of the burning bush. Later, Moses will ask Him name and He will respond, “I AM that I AM” is His name. But isn’t this the Angel of the LORD? Yes it is. And therefore the Angel of the LORD is eternal God Himself.
Here’s another interesting verse, Psalm 34:7:
The angel of the LORD encampeth round about them that fear him, and delivereth them.
Obviously, since the Angel of the LORD is to be feared (and only God is to be feared) and accomplishes deliverance (salvation) for those that do fear Him---it can only be the God and Saviour Jesus Christ who is in view. And Jesus Christ is not just the Saviour He is also the judge of mankind. God has given to Him authority to execute judgment, John 5:27:
And hath given him authority to execute judgment also, because he is the Son of man.
This is why we see the Angel of the LORD often bringing judgment (as is the case in 1 Chronicles chapter 21). It is a picture of Christ carrying out His role as Judge of the corporate church (as is the spiritual picture being painted as 70,000 die in Jerusalem at the hand of the Angel of the LORD); or as the Judge of the world.