Robert Louis Stevenson presents a story about the evil within man in his book Dr. Jekyll and Mr. Hyde. The author contrasts the two main characters, Dr. Jekyll, a wise elderly doctor of kind hearted spirit twoard his friends and aquantances, with Mr. Hyde, an evil murderer shrouded in mystery. The two are assumed to be enemies but the speculation of their relationship by the reader changes throughout the story leading the reader to believe criminal activity is involved. 
The myster is unfolded by Dr. Jekylls friends and servants, Dr. Lanyon a former campanion, who has cut ties with Dr. Jekyll, Mr. Utterson, Jekyll's lawyer, and Mr. Poole who was a servant of Dr. Jekyll for 20 years. None of them are exactly sure what is going on, but it is certain that Dr. Henry Jekyll is hiding something from all of them.
Mr. Hyde is introduced as a strange and scary figure who tramples over a little girls in the street without thinking a thing about it. Then about a year later he brutally murders Sir Danvers Carew with a bat, stomping and cracking his bones. The final appearence of Mr. Hyde is when he comes to Dr. Lanyon which we see in his letter to Utterson, and shows him that Mr. Hyde and Dr. Jekyll share the same body, and that Hyde has slowly been taking over so that Henry Jekyll will no longer exsist. 
Although the story is not biblically inspired, it does illistrate the fact the humans can have two natures. The first being sin, which we are born with, and the second being a desire to serve God which we obtain when we accept His gift of salvation and the Holy Spirit comes to dwell in our life. Paul describes the struggle between the new, and old natures, as a dificult battle which we won't have complete victory in until we are with Christ in heaven. However christians must seek God's will be reading His word, and serving Him. In this way can obtain some victory against sin in our life.