"Where did Satan come from? Was the devil an angel who went bad?"
The origins of Satan has long been an interesting study filled with stories, myths, and unconventional interpretations. In these later years the role of Satan has been in flux as the church and science has attributed much of the world's "evil" to the devices and whims of humanity run amuck. However, before we examine the stories of his origin, let us look to the history of the ancient Israelite beliefs.
In the Hebrew scriptures (the Old Testament) Satan is referenced a total of fourteen times. Of those fourteen references, only three fall outside of the book of Job. In our traditional understanding, Satan is the author of the world's evil and is responsible for temptations, many disasters and tragedies, and virtually all "bad things" that happen. However, in the early Hebrew understanding this concept was completely foreign. All fortunes and misfortunes were attributed to God. God made the sun to rise and the rain to fall. God was responsible for illnesses, famines, wars, and death. God was even responsible for testing (NRSV) or tempting (KJV) people.
The concept of Satan rose during and following the Babylonian captivity of Judah in the fourth and fifth centuries BCE. During this period the influence of the Persians began to weigh heavily upon the Israelites. Persia were acquainted with the embodiment of evil in the form of one Shatan. This evil one was the author of chaos and evil in the world as they understood it. The Israelite faith adopted and adapted this figure and God became the creator of good and Satan became the doer of evil.
As to the references in the Old Testament, the earliest passages are those contained in the book of Job which was most likely written during the Babylonian exile. Here Satan is pictured as a prosecuting attorney who is also in charge of sting operations i.e., trying to test/tempt the faithful. In Zechariah (3.1-2) Satan is again pictured as an accuser of the faithful. Only in 1st Chronicles 21.1 is Satan seen as one who sets evil within human hearts and most experts agree this verse was added quite late to the writings, well after the Babylonian exile.
A fully developed theology of Satan is not demonstrated scripturally until the New Testament. There we find the devil blamed for virtually all testing and tempting. Indeed, James 1.13 asserts that God does not tempt anyone, clearly a theological shift from the ancients.
But where did Satan come from? The stories of Satan's rise to power is nowhere explained clearly in scripture, although there have been some rather unconventional interpretations made in this regard. In Isaiah 14 there is a lament for and against the king of Babylon for his deeds against Judah. In the midst of this passage we read, "How you are fallen from heaven, O Day Star, son of Dawn! How you are cut down to the ground, you who laid the nations low!" (Isaiah 14.12). The phrase "O Day Star" is a translation of the word lucifer that has become known (from this lone passage) as the proper name for Satan. From this passage rose the story that Satan was once an angel who went bad.
Further passages used to support this notion include Daniel 8.10 "It threw down to the earth some of the host and some of the stars." In ancient days, stars were often ascribed as angels shining in the darkness. The casting down of some of the stars was interpreted as the casting out of Satan and his league. Indeed, in the book of Revelation we read of a war in heaven "And war broke out in heaven; Michael and his angels fought against the dragon. The dragon and his angels fought back, but they were defeated, and there was no longer any place for them in heaven. The great dragon was thrown down, that ancient serpent, who is called the Devil and Satan, the deceiver of the whole world he was thrown down to the earth, and his angels were thrown down with him" (Revelation 12.7-9). Although the Revelation is most often thought to be an account of the future, here many have re-interpreted this passage to be the story of how Satan was cast from heaven in the past.
The origins of Satan may have come through the Persian influences over Israel, from the notion of an angel chosen to be a prosecuter/accuser of the faithful, or from a war in heaven whereas Lucifer and his cronies were cast out. In any event, the role of Satan today is under consideration, but no matter how the devil comes out, there is no doubt evil exists and is rampant in our world. Who we "blame" is yet another matter.