Translating the WordStanding behind the translation "Satan" in almost all translations is the Hebrew word hasatan. In Hebrew the "ha" is the definite article. If we were, therefore, to take the name directly over into English it would be "The Satan." Every time the word is used in the first two chapters of Job (an amazing 12 times), the creature is called hasatan. Never once is it called "satan." Thus, as any good translator must do, you must render what you have. It is "The Satan." Therefore, the word hasatan is more of a title than a proper name, more of a designation than an appellation. The creature first appearing in Job 1:6 is hasatan. He/she/it also appears in Zech.3:1-2 as hasatan. The root s-t-n in Hebrew means "adversary" or "opponent," so the best translation of hasatan in Job 1-2 is "The Adversary" or "The Opponent." We will learn better what his name means when we understand what it does.
The Satan in Job 1-2
The first thing we notice about hasatan in Job 1 is that it appears in the presence of God along with the "sons of God." The picture assumed by Job 1 is similar to what is described in I Kings 22 where Micaiah ben Imlah says:
19 "Then Micaiah said, "Therefore hear the word of the LORD: I saw the LORD sitting on his throne, with all the host of heaven standing beside him to the right and to the left of him. 20 And the LORD said, 'Who will entice Ahab, so that he may go up and fall at Ramoth-gilead?' Then one said one thing, and another said another, 21 until a spirit came forward and stood before the LORD, saying, 'I will entice him.' 22 'How?' the LORD asked him. He replied, 'I will go out and be a lying spirit in the mouth of all his prophets.' Then the LORD said, 'You are to entice him, and you shall succeed; go out and do it.'"
That is, a few Old Testament texts assume that God, though One, is surrounded in heaven by a sort of heavenly court, with messengers coming to and fro to do God's bidding and report on affairs throughout the kingdom. It is certainly an anthropomorphism--Near Eastern and Egyptian understanding of kingship also had a royal figure who employed many functionaries to gather data for and report back to the king. It is in this context that hasatan, The Adversary appears.
Second, it isn't clear whether the Adversay is a member of the heavenly court or is a sort of interloper. Verse 6, which says that The Satan was among them (the "sons of God"😉 is ambiguous on this question. The text says that the sons of God came to stand before God, "and The Satan also came among them." We can infer neither that The Satan was part or wasn't a regular part of the group. We do know, however, that when God speaks to The Satan, it is on cordial or even friendly terms.
Third, following up on the point just made, there is no indication that The Satan in Job is to be identified with Satan in the New Testament. That Satan is unalterably opposed to God and is not portrayed as living or traveling in the heavenly court with God. Satan in the New Testament portrayal is already in hell with his minions. There is no way that The Satan in Job and Satan in the New Testament share the same world.
Fourth, when the text mentions the name as The Satan or the Adversary, we should realize that the primary adversary of this creature is Job and not God (while the New Testament Satan is inveterately opposed to God). As a matter of fact, God strikes up a rather amiable conversation with The Satan. The Satan isn't out to "get Job," as it were. In fact, it is God who is seemingly unsure of Job's absolutely loyalty, and The Satan proposes a test to determine the genuineness of Job's faith. Thus, The Satan devises a scheme that goes against Job and not God. Rather than opposing God, as the Book of Job portrays it, The Satan is actually helping God figure out whether or not Job's piety is induced by favorable economic and familial blessings.
Conclusion
The most that can be said by those who want to maintain that The Satan in Job is the same as Satan in the New Testament is that The Satan has certain "personality traits" which, if "developed" might help him morph in to Satan. However, most conservatives don't like to think or argue like this. Thus, if they are honest with the text they need just to render its name The Satan or The Adversary and see this creature as a sort of agent of or subordinate to God whose special task it is to bring human conduct to God's attention. The world assumed by the author of Job is one of royal courts, where kings send their ministers out to perform various functions. God, too, must be set up like a human king. The Satan, then, may be crafty and sneaky, but God doesn't seem to be able to see through the Satan's sneakiness (which creates a bit of a problem for those maintaining the absolute sovereignty and ominscience of God). The Satan, however, is not a totally evil figure, trying to wreck the designs of a good God.