Joyfuldead said:
who was that during Jesus' fast in the desert, somewhere round matthew 4.
Where a satan does appear as an angel, he/she is clearly a member of God's court and plays the role of the Accuser (possibly one of a number), much like a prosecuting attorney for God. Such a view is found in the prologue to the Book of Job, where a satan appears, together with other celestial beings, before God, replying to the inquiry of God as to whence he had come, with the words: "From going to and fro in the earth, and from walking up and down in it" (Job 1:7). Both question and answer, as well as the dialogue which follows, characterize this satan as that member of the divine council who watches over human activity, but with the purpose of searching out men's sins and appearing as their accuser. He is, therefore, the celestial prosecutor, who sees only iniquity; he persists in his evil opinion of Job even after he has passed successfully through his first trial by surrendering to the will of God, whereupon the satan demands another test through physical suffering.
It is evident from the prologue that satans have no power of independent action, but requires the permission of God, which he may not transgress. A satan is not an opponent of God. This view is also retained in Zechariah 3:1-2, where the satan is described as the adversary of the high priest Joshua, and of the people of God whose representative the hierarch is; and he there opposes the "angel of the Lord," who bids him be silent in the name of God. In both of these passages satan is a mere accuser who acts only according to the permission of the Deity.
In I Chronicles 12:1 satan appears as one who is able to provoke David to destroy Israel. The Chronicler (third century BCE) regards satan as an independent agent, a view which is the more striking since the source whence he drew his account (II Samuel 24:1) speaks of God Himself as the one who moved David against the children of Israel. Since the older conception refers all events, whether good or bad, to God alone (I Samuel 16:14; I Kings 22:22; Isaiah. 45:7; etc.), it is possible that the Chronicler, and perhaps even Zechariah, were influenced by Zoroastrianism.