Satan, as you describe, is a Christian invention that did not exist until the New Testament. Before the New Testament was written, the serpent in the garden, Satan in Job, and Lucifer were all separate characters. In fact, Lucifer originated as another name for Venus (the Morningstar) which was strongly associated with the Greek god Apollo.
If you look at the character of Satan in the Book of Job, you have an entity that is not the adversary of God, but is instead the adversary of humanity. Satan plays the role of prosecuting attorney, pointing out Jobs's imperfections and suggesting to God that he tries Job's faith and loyalty. It's important to note that while the trials dealt to Job was the suggestion of Satan, God agreed to carry out those trials and was the one to inflict those trials on Job.
The truth of the matter is that Satan, as a theological concept, is deeply problematic for the Christian religion. It has been used to justify horrors time and again. One only needs to consider the Spanish Inquisition or the Salam Witch Trials to see the havoc that belief in this mythological entity has caused. It's also a means of escaping responsibility... "Satan made me do it."