A mammoth literature, cultural landmark, and symbolic complex, pertaining to the sale of destination of one's essence beyond the organismic decease. Allegiance, alliance, and plane of participation all contribute toward a diversity, inclusive of cautionary tale, transgressive rebellion (to have written or published it at all), and redemptive salvation (e.g. Neo-Gnosticism).
Primarily a response to seeking knowledge over faith (and being hamstringed by an absence of employment of critical thinking).
Secondarily a response to seeking joy and pleasure in the short term, with careless disregard (e.g. sale) of future destination.
Its intersection with Satanism is oblique, and inconsistent. Insofar as Mephistopheles has any interest in Faustus' welfare, it is primarily to trick, trap, or snare the tragic figure into torment and accusation, then to have him gnashing his teeth or making off with the primary female lead (e.g. Helen of Troy), saved and redeemed to the correct god.