In Goethe's Faust Part I, we see the main character who is unhappy and desiring more knowledge; he even contemplates becoming part of the cosmos through suicide. He lives an academic life, separate from the company of others. Knowledge is what he seeks, but the human side of life does not appeal to him. When Mephistopheles (Mephisto) is given permission by The Lord to tempt Faust to test his dedication to The Lord, Mephisto does all he can, within Faust's challenge and wager.
In Part I, Faust seduces a young, respectable girl, Margaret (Gretchen). She becomes pregnant and for the most part, he has little concern for her. She ends up in prison: she has mistakenly poisoned her mother with a sleeping draught, but the worst blemish on her soul is the drowning of her illegitimate child. At this point, Faust tries to help her escape, but she refuses. She realizes what she has done and, when she dies, The Lord takes her to Heaven in light of her penitence and wish to be one with The Lord again. Faust is devasted over the end of the life of the innocent woman he has, essentially, destroyed.
In Part II, Faust is tranformed from a Romantic figure to a Classical hero. He ardently pursues Helen of Troy. When he wins her heart, they retreat to a paradise and she has a child. However...
Their son is the combination of the Classical and Romantic, and he seeks to gain knowledge and experience beyond his years. He is warned of the dangers, but casts himself off a cliff to his death.
Helen is summoned by their son from Classical Hades and must leave Faust to go to him, and Faust "floats away on a cloud." This description seems incongruous by comparison to the Faust we see in Part I.
Eventually, Faust decides to attempt the impossible: he wants—for the good of mankind—to take back land that the ocean has overrun, and so he "takes on" nature. When he tries to buy land owned by an old peasant couple for this task, they refuse. Faust asks Mephisto to evict and relocate them to a new home, but they are killed instead. Faust is irate and devastated that, because of his instructions, the old couple lose their lives. And so...
...this begins his spiritual penance.
Faust remains, however, dedicated to his task of restoring land to humanity. Want, Debt, Distress, and Care visit Faust. Care tells Faust that mankind will never find "peace in life" and blinds Faust when he disagrees. But Faust wants to finish this task--he wants the moment to stay so he can finish. He has a vision of success:
Faust has a vision of people living on his reclaimed lands...
Finally, "proudly," he repeats his wager with Mephisto and instantly he dies. He is taken to Heaven before Mephistos or his "demons" have the chance to take his soul. The Lord saves Faust, through Gretchen's intercession, and he finds Gretchen waiting for him. Faust may need still to work to attain complete salvation but he may do so in Heaven.
In the second part of the play, Goethe is concerned that Faust experience the life he had formerly shunned but without any trace of Romanticism; he even becomes philanthropic. Ironically, as Mephisto tries to win the wager and take Faust's soul to its eternal damnation, Faust seems to be moving of his own accord to being a better person: toward salvation, though the Faust in Part I doesn't seem too concerned with this. God sees the good in Faust, and he is saved from Mephistopheles at the end and reunited with Gretchen.