"This night I'll conjure tho' I die therefore...."
See in text (Scene 1)
Notice that Faustus recognizes the danger in his actions. He mentions the death that comes with engaging in necromancy and decides that power is more important to him. This end to Scene 1 simultaneously foreshadows Faustus's tragic end and demonstrates the character's careless vanity.
"by aspiring pride and insolence..."
See in text (Scene 3)
The characteristics Mephistophilis ascribes to Lucifer underscore the traits that Faustus has shown. Lucifer's story foreshadows Faustus's ultimate downfall and tragic end; like Lucifer, Faustus's insolence and pride will cause him to fall.
"delight his mind...."
See in text (Scene 5)
When Faustus beings to contemplate his inevitable damnation, Mephistophilis distracts him with "delight." This foreshadows the nature of the pact that Faustus has just signed: it will not bring him the power that he imagined but rather simply distract him from his damned reality.
"To guide thy steps..."
See in text (Scene 12)
The Old Man is a memento mori, a Renaissance and Medieval literary trope, in which a ghost, skeleton, or person close to death would appear to remind the main character (and by extension the audience) of the need to repent in the face of inevitable death.