How does Marlowe's use of language contribute to Dr. Faustus' characterization in Part 1, Scene 3?
At first in Lines 14 and 15, language is used to characterize Faustus as fearful of his task, though confident in his skill and ability to fulfill all requirements, which Faustus has listed in Lines 1 through 13. Next, language is used show that Faustus, though previously fearful, is nonetheless arrogant and demanding: "I charge thee to return and change thy shape;" (24). Language further shows that Faustus has a serious misconception of the traits ans qualities and agenda of Mephistophilis: "Such is the force of magic and my spells:/ ... / That canst command great Mephistophilis" (32, 34).
Marlowe characterizes Faustus quite clearly as one who has great skill and expertise but is yet not above feeling fear in a new venture. Nonetheless, because of his great skill and expertise--which ironically prove to be his downfall--he is arrogant and demanding,. He goes so far in his arrogance to suppose that his first impulse--which is to tell Mephistophilis to "change into something more comfortable" to Faustus' perception--is an appropriate one to voice. His arrogance carries him even further into his fatal misconception that Mephistophilis' compliance indicates that well-wrought magic will render Mephistophilis tame and harmless: "Full of obedience and humility!" (31).