See Old and New Testaments.
Not very helpful. Apart from the Book of Job and a reference in Zechariah, Satan is rather conspicuous by his absence in the Old Testament. There is a kind of evolution of the concept Malach Jahweh (spirit or angel of God) into a personification of Satan as a quasi-independent force - most prominent in Job, though there Satan is given express permission to do God's dirty work. The reference in Zechariah seems to indicate a being who has gone a bit too far in his activities and receives the divine smack on wrist.
Let's not forget those verses in Isaiah, which seem to do away with an independent devil altogether:
"[6] I am the LORD, and there is no other.
[7] I form light and create darkness,
I make peace and create evil,
I am the LORD, who do all these things."
All this is very different from Satan as he appears in the NT, particularly one reference in John's gospel, where he appears as a force in a scenario of almost absolute cosmic dualism ("Ye are of your father the Devil ...etc")
Do you believe in a literal personal devil? Be nice if you'd lay your cards on the table.