This has several major driving factors though. Faust did not make a "pact" with Mephisto or accept his service in exchange for his soul. Faust made a bet with Mephisto, with the agreement being that if Faust was not entirely satisfied in every aspect that he would lose the bet and Mephisto would win his soul. Also, God allows Mephisto to engage in this bet with Faust knowing that Faust will emerge a morally true person and ultimately return to God and not Mephisto. This alone should show what the outcome will be, showing that if God in his infinite wisdom knows that Faust will ultimately remain a good soul, then how could Mephisto ever hope to change the outcome?.
In addition Faust is involved in many activities that can be considered to be amoral. His great desire to be with Gretchen is one of the first of a series of actions that Faust commits that seem to send him further from virtue and closer to Mephisto's control. This however is not entirely Faust's fault, because he was under the influence of Mephisto's potion when he began his pursuit of Gretchen. Under Mephisto's potion he is unable to think clearly and is controlled by his passion rather than his own mind and thoughts. Faust ultimately becomes responsible for the imprisonment of Gretchen by influencing her actions, and after she is imprisoned, Faust moves on. This would seem to represent the loss of control by Faust and the power of Mephisto to bend Faust's will. It symbolizes more that Faust is a reasonable person, and that only when influenced by Mephisto does he lack virtue. When viewed from this perspective, it foreshadows Faust's return to virtue and salvation.
Faust also engages in other activities that seem deserving of eternal damnation. Unfortunately, his actions become progressively worse through the play. Although he was under the influence of Mephisto when he pursued Gretchen, his later actions are of his own will.
