How we cite our quotes: All quotations are from Gladiator.
Quote #1
MAXIMUS: What we do in life, echoes in eternity.
This is one of the most famous lines from the film, and the film's first statement of the idea that what we do in life can ensure that our memory lives on.
Quote #2
MARCUS AURELIUS: When a man sees his end he wants to know there was some purpose to his life.
Marcus Aurelius' comments to Maximus pick up the same theme—the survival of our deeds after the death of our bodies. He wants to know "there was some purpose" because he wants to be remembered after death (which is just around the corner) for doing good, not for waging war and other things.
Quote #3
PROXIMO: I did not pay good money for you for your company. I paid it so that I could profit from your death.
For Proximo, death is a business. For him, life only has value insofar as it has a monetary value. There may be a tiny bit of foreshadowing here. While Proximo doesn't profit from the deaths of his latest batch of gladiators, Rome will eventually profit from Maximus' death (they will be rid of an evil emperor).