Faust is unsatisfied with his life as a scholar and becomes depressed. After an attempt to take his own life, he calls on the Devil for further knowledge and magic powers with which to indulge all the pleasure and knowledge of the world. In response, the Devil's representative, Mephistopheles, appears. He makes a bargain with Faust: Mephistopheles will serve Faust with his magic powers for a set number of years, but at the end of the term, the Devil will claim Faust's soul, and Faust will be eternally enslaved.
During the term of the bargain, Faust makes use of Mephistopheles in various ways. In Goethe's drama, and many subsequent versions of the story, Mephistopheles helps Faust seduce a beautiful and innocent young woman, usually named Gretchen, whose life is ultimately destroyed when she gives birth to Faust's illegitimate son. Realizing this unholy act, she drowns the child and is held for murder. However, Gretchen's innocence saves her in the end, and she enters Heaven after execution. In Goethe's rendition, Faust is saved by God via his constant striving—in combination with Gretchen's pleadings with God in the form of the eternal feminine. However, in the early tales, Faust is irrevocably corrupted and believes his sins cannot be forgiven; when the term ends, the Devil carries him off to Hell.
Although Mephistopheles appears to Faustus as a demon – a worker for Lucifer – critics claim that he does not search for men to corrupt, but comes to serve and ultimately collect the souls of those who are already damned. Farnham explains, "Nor does Mephistophiles first appear to Faustus as a devil who walks up and down on earth to tempt and corrupt any man encountered. He appears because he senses in Faustus' magical summons that Faustus is already corrupt, that indeed he is already 'in danger to be damned'."
Mephistopheles is already trapped in his own Hell by serving the Devil. He warns Faustus of the choice he is making by "selling his soul" to the devil: "Mephistophilis, an agent of Lucifer, appears and at first advises Faust not to forego the promise of heaven to pursue his goals".Farnham adds to his theory, "...[Faustus] enters an ever-present private hell like that of Mephistophiles".