The Renaissance was a great intellectual and cultural movement based on the rediscovery of ancient learning. It gave rise to a humanistic philosophy which put man, not God, at the center of the universe, and that's precisely how Doctor Faustus sees himself.
Like the archetypal Renaissance man he is, he has a deep passion for knowledge, an insatiable desire to assert himself against a world rapidly becoming more and more intelligible. There's a restlessness about him, a sense that the world's somehow not big enough for him. He wants to explore, to discover, to know and to learn. But more than anything else, he seeks the power that increased knowledge can bring. For Doctor Faustus, as much as any Renaissance man, knowledge is indeed power, and the more he can have of both the better, even if it means selling his soul to the Devil.