Marlowe doesn't give very much background information, but there is enough from the Chorus and from Faustus' introductory soliloquy to give us some idea of his life before necromancy (magic). When we meet Faustus, he is an academic with doctoral degrees in theology, economics, medicine and other fields. Each of these he reviews to himself in his soliloquy as he decides to which field he will devote the remainder of his academic career of teaching students. It is necromancy that he decides upon.
... Divinity, adieu!
These metaphysics of magicians,
And necromantic books are heavenly;
This glimpse of his background and intellectual prowess and pursuits confirms what the Chorus has already said at the opening of the play. They tell us that Faustus was born to common, not high born or educated, parents and that he was sent to be raised by relatives in "Wertenberg" [Wittenberg], a Protestant university town. Here he quickly mastered Theology and was awarded a doctoral degree. The Chorus then uses an allusion and a metaphor to tell us that his arrogance and pride led him to daring that would prove to be his undoing and downfall: he chose the "devilish exercise," necromancy.
Till swoln with cunning, of a self-conceit,
His waxen wings did mount above his reach,
And, melting, heavens conspir'd his overthrow;
His attitude about himself is revealed in his soliloquy. He is arrogant and greedy; he is disinterested in religious morality and he want to be a deity.
Be a physician, Faustus; heap up gold,
And be eterniz'd ...
Here, Faustus, tire thy brains to gain a deity.
One opinion is given us by the Chorus. Faustus views the charms of magic as more valuable and dear than the theology and religion he formerly held to.
Nothing so sweet as magic is to him,
Which he prefers before his chiefest bliss [theology]:
In summary, Faustus started with nothing but his natural intelligence and was given everything including Protestant Theology [this is early in Luther's Protestant Reformation]. Yet now he thinks all his learning useless and irrelevant. He thinks himself better than his circumstances and wants to dance with devils in magic, devils he also thinks himself better than:
Such is the force of magic and my spells:
No, Faustus, thou art conjuror laureat,
That canst command great Mephistophilis: