Consummatum Est

When Doctor Faustus performs a blood ritual as he signs his soul over to Lucifer, he utters the words "Consummatum Est". This is a direct reference to Christ's death on the cross, and though Faustus may be committing spiritual suicide, it is quite profane. When he makes this reference, he is making his allegiance to Satan a counterfeit and an inversion of the accomplishments of Christ's death on the cross. Furthermore, when using Christ's words, he is either elevating himself or profanely degrade Christ, both of which are demonic in nature (ie. like Lucifer). In either case, Lucifer later rebukes Faustus for even mentioning anything associated with Christ.