Sons of God and Satan in Heaven?

Who are the sons of God in Job, and why is Satan permitted access to the Heavenly throne room? It seems as if the Satan of the Old Testament isn't the same character as the one in the New Testament.

The book of Job opens with a scene in the Heavenly throne room where Satan meets with the Lord:

Job 1:6 Now there was a day when the sons of God came to present themselves before the LORD, and Satan also came among them.
Job 1:7 The LORD said to Satan, “From where do you come?” Then Satan answered the LORD and said, “From roaming about on the earth and walking around on it.”
Job 1:8 The LORD said to Satan, “Have you considered My servant Job? For there is no one like him on the earth, a blameless and upright man, fearing God and turning away from evil.”

First, the term "sons of God" (ben elohim) is used only two places in the Bible. Once in Genesis 6 and in Job. In the three instances in Job, the context leaves no doubt the term is a reference to the angelic realm. The sons of God are the angels God created, including Satan himself who was the highest angel.

We read about Satan’s origins in Ezekiel 28:

Ezek. 28:12 “Son of man, take up a lamentation over the king of Tyre and say to him, ‘Thus says the Lord GOD,
   “You had the seal of perfection,
   Full of wisdom and perfect in beauty.
Ezek. 28:13  “You were in Eden, the garden of God;
   Every precious stone was your covering:
   The ruby, the topaz and the diamond;
   The beryl, the onyx and the jasper;
   The lapis lazuli, the turquoise and the emerald;
   And the gold, the workmanship of your settings and sockets,
   Was in you.
   On the day that you were created
   They were prepared.
Ezek. 28:14  “You were the anointed cherub who covers,
   And I placed you there.
   You were on the holy mountain of God;
   You walked in the midst of the stones of fire.
Ezek. 28:15  “You were blameless in your ways
   From the day you were created
   Until unrighteousness was found in you.
Ezek. 28:16   “By the abundance of your trade
   You were internally filled with violence,
   And you sinned;
   Therefore I have cast you as profane
   From the mountain of God.
   And I have destroyed you, O covering cherub,
   From the midst of the stones of fire.

Satan was created to be the “covering cherub” guarding the mercy seat of the Heavenly tabernacle until he fell in sin and was cast out of the tabernacle as profane.

Nevertheless, the scriptures make clear Satan still has access to the throne room of God at least for a time. Clearly, Job shows Satan visiting the throne room at times when the entire assembly of the sons of God (i.e., the angels) are present (see Job 2:1).

Why does the Lord permit Satan such free access to the throne? Revelation 12 gives us a possible answer:

Rev. 12:7 And there was war in heaven, Michael and his angels waging war with the dragon. The dragon and his angels waged war,
Rev. 12:8 and they were not strong enough, and there was no longer a place found for them in heaven.
Rev. 12:9 And the great dragon was thrown down, the serpent of old who is called the devil and Satan, who deceives the whole world; he was thrown down to the earth, and his angels were thrown down with him.
Rev. 12:10 Then I heard a loud voice in heaven, saying, “Now the salvation, and the power, and the kingdom of our God and the authority of His Christ have come, for the accuser of our brethren has been thrown down, he who accuses them before our God day and night.
Rev. 12:11 “And they overcame him because of the blood of the Lamb and because of the word of their testimony, and they did not love their life even when faced with death.
Rev. 12:12 “For this reason, rejoice, O heavens and you who dwell in them. Woe to the earth and the sea, because the devil has come down to you, having great wrath, knowing that he has only a short time.”

Revelation 12 describes a moment in the future, in the middle of the seven year Tribulation on earth, when the Lord will finally and forever bar Satan and his demons from access to the heavenly throne room. Revelation 12 says that the expulsion of Satan means terrible things are in store for the inhabitants of the earth because Satan will understand he has little time remaining before Christ's return.

Once Satan is barred from the throne room, he becomes desperate like a cornered animal. He will be enraged and seeking to strike back, and he takes his vengeance out on the in habitants of the earth. Since the Lord knows this will be the result of barring Satan from Heaven, the Lord has mercifully delayed this moment until the end of this age.

Satan in the Old Testament is not different than the Satan we see portrayed in the New Testament. On the contrary, the portrayal of Satan in Job is exactly like the Satan described in the New Testament, especially in Revelation. Notice in Job we see Satan making false accusations against Job, a man the Lord describes as an upright and God-fearing servant. Then in Revelation 12 we’re told that the Satan expelled from Heaven is the very same serpent from the Old Testament, the one who accuses the brethren. The Revelation 12 reference to Satan accusing is a direct reference to Satan in Job.