FAUSTUS
How am I glutted with conceit of this!
Shall I make spirits fetch me what I please,
Resolve me of all ambiguities.
[…]
I'll have them read me strange philosophy
And tell the secrets of all foreign kings. (1.1.76-78, 84-85)
Faustus's quest for knowledge transforms into a need to learn the "secrets of all foreign kings," suggesting how much Faustus's desire for knowledge is tied up with his equally strong need to have a ton of power.
CORNELIUS
He that is grounded in astrology,
Enriched with tongues, well seen in minerals,
Hath all the principles magic doth require.
Then doubt not, Faustus, but to be renowned
And more frequented for this mystery
Than heretofore the Delphian oracle. (1.1.131-136)
Faustus's friend tells him he's already well suited to learn magic because of his education in astrology, languages, and alchemy. Now isn't that convenient? Hmm… maybe Faustus was predestined for magic ages ago…
Quote 33
FAUSTUS
I am resolved, Faustus shall not repent.
Come, Mephistopheles, let us dispute again
And reason of divine astrology.
Speak; are there many spheres above the moon?
Are all celestial bodies but one globe,
As is the substance of this centric earth? (2.3.30-35)
While Faustus hems and haws, wondering if he should regret his decision to make a deal with Lucifer, it's Mephistopheles that helps convince him he made the right call, because Mephistopheles promises that Dr. F will gain a ton of knowledge as a result of handing over his soul. In a way, this means that knowledge has become a kind of idol for Faustus—something that has taken the place of God for him.