Just as the Serpent, Iago can easily be seen as the evil force in the story. It is possible that Iago too is not meant to be taken literally, but to show the influence of evil in the characters. The characters who act on the influence of evil received their punishment: Roderigo, who loves Desdemona, goes on to die because of that; Cassio, who drinks too
much at the celebration, goes on to be severely injured by Roderigo; Emilia, who steals the handkerchief, goes on to die because of that; and Othello, who kills Desdemona, goes on to kill himself. This also provides a reason why Othello does not ask any other character about Desdemona's unfaithfulness, that is, because it is his own suspicion the entire time.
Iago shows such pure evil that the only possible explanation for his lack of conscience is that he represents the evil intentions of all the characters in the play. The fact that Iago is married to Emilia could be seen simply as Emilia's closeness to evil and this view would also explain how their relationship is so unlike that of Othello and Desdemonas'. Instead of Iago physically murdering Roderigo and Emilia, it might be seen that in following evil, the two commit their own "original sins" that prevent them from a much longer life just as Adam and Eve. Emilia, in stealing the handkerchief, can be seen as an Eve figure because not only does she follow Iago in taking it, but she also plays a major part in the influence of Othello's "original sin." Othello, being an Adam figure, is deceived by both Iago and Emilia. Othello's "original sin" that leads him to his own death is the murdering of Desdemona. This loss of the paradise they once had and their innocence can be contributed mainly to Iago. The similarities of "Othello" and the creation story support Iago as a symbol for evil or even the devil. Iago is like the proverbial devil that hovers over one shoulder telling you to do badly, but the angel on the other shoulder is shown through the characters' consciences, such as when they question his accusations. The characters that follow Iago all face punishing consequences. At the very end when Othello realized the wrong he had committed, it is the same time that Iago, no long being influential, is wounded. The fact that he does not die, but is imprisoned shows that the characters will think twice about following evil after this incident, but that it will remain an influence.