The Bible and history present us with enough evidence to refute the false teaching that Job was an Edomite. Here is the carnal and spiritual evidence.
Job is Only Alleged to Be An Edomite
God Only Ever Showed His Word to Israelites
Psalms 147:19-20
[19]He sheweth his word unto Jacob, his statutes and his judgments unto Israel.
[20]He hath not dealt so with any nation: and as for his judgments, they have not known them. Praise ye the LORD.
Job Gains Understanding But Esau Has None
Job 28:28
[28]And unto man he said, Behold, the fear of the Lord, that is wisdom; and to depart from evil is understanding.
Obadiah 1:7
[7]All the men of thy confederacy have brought thee even to the border: the men that were at peace with thee have deceived thee, and prevailed against thee; they that eat thy bread have laid a wound under thee: there is none understanding in him.
Every One of the Mount of Esau is Doomed to Destruction
Obadiah 1:9
[9]And thy mighty men, O Teman, shall be dismayed, to the end that every one of the mount of Esau may be cut off by slaughter.
Matthew 13:30,38-39
[30]Let both grow together until the harvest: and in the time of harvest I will say to the reapers, Gather ye together first the tares, and bind them in bundles to burn them: but gather the wheat into my barn.[38]The field is the world; the good seed are the children of the kingdom; but the tares are the children of the wicked one;
[39]The enemy that sowed them is the devil; the harvest is the end of the world; and the reapers are the angels.
Jobab is NOT Job
The children of Esau came to fight the sons of Jacob and Egypt to free their brother Zepho
Jasher 58:14-15
[14]And it came to pass at the end of many days and years, when the children of Esau were dwelling quietly in their land with Bela their king, that the children of Esau were fruitful and multiplied in the land, and they resolved to go and fight with the sons of Jacob and all Egypt, and to deliver their brother Zepho, the son of Eliphaz, and his men, for they were yet in those days slaves to Joseph.
The children of the east came to battle against Jacob and Egypt in alliance with Esau
[15]And the children of Esau sent unto all the children of the east, and they made peace with them, and all the children of the east came unto them to go with the children of Esau to Egypt to battle.
Joseph, Jacob and Egypt slew the Edomites AND the children of the east.
Jasher 58:19-20
[19]And the Lord gave all the mighty men of Esau and the children of the east into the hand of Joseph and his brethren, and the people of the children of Esau and the children of the east were smitten before Joseph.
The children of Esau got weak when their king died in battle
[20]And of the people of Esau and the children of the east that were slain, there fell before the sons of Jacob about two hundred thousand men, and their king Bela the son of Beor fell with them in the battle, and when the children of Esau saw that their king had fallen in battle and was dead, their hands became weak in the combat.
The children of Esau took a king from the children of the east. They were afraid of and hated Jacob after the battle.
Jasher 58:25-28
[25]And all the people of the children of Esau, and the children of the east, returned in shame each unto his city, for all the mighty men that were with them had fallen in battle.
[26]And when the children of Esau saw that their king had died in battle they hastened and took a man from the people of the children of the east; his name was Jobab the son of Zarach, from the land of Botzrah, and they caused him to reign over them instead of Bela their king.
[27]And Jobab sat upon the throne of Bela as king in his stead, and Jobab reigned in Edom over all the children of Esau ten years, and the children of Esau went no more to fight with the sons of Jacob from that day forward, for the sons of Esau knew the valor of the sons of Jacob, and they were greatly afraid of them.
[28]But from that day forward the children of Esau hated the sons of Jacob, and the hatred and enmity were very strong between them all the days, unto this day.
Other Nations Also Ruled In Edom
Dukes of Esau
Genesis 36:40
[40]And these are the names of the dukes that came of Esau, according to their families, after their places, by their names; duke Timnah, duke Alvah, duke Jetheth,...
Dukes of the Horites
Genesis 36:29-30
[29]These are the dukes that came of the Horites; duke Lotan, duke Shobal, duke Zibeon, duke Anah,[30]Duke Dishon, duke Ezer, duke Dishan: these are the dukes that came of Hori, among their dukes in the land of Seir.
Foreign Rulers of Edom
Genesis 36:31-33
[31]And these are the kings that reigned in the land of Edom, before there reigned any king over the children of Israel.
[32]And Bela the son of Beor reigned in Edom: and the name of his city was Dinhabah.
[33]And Bela died, and Jobab the son of Zerah of Bozrah reigned in his stead.
Same Jobab who was a foreign ruler in Edom is the Jobab of Jasher 58:26. A child of the east NOT an Edomite.
In Conclusion
Jobab was a king from the children of the east not Esau. God only ever dealt with Jacob. The children of the east fought Jacob to rescue Esau. The Bible promises annihilation to Esau and his children. Esau cannot be righteous according to scripture because he has NO understanding. Other nations ruled in Edom and lastly, the claim that Job is an Edomite is even disputed among Edomites. Therefore it is impossible that Job or any other person in the Bible that God deals with be anything but an Israelite. And that's the gospel.