How we cite our quotes: All quotations are from Star Wars: A New Hope.
Quote #7
VADER: Your powers are weak, old man.
OBI-WAN: You can't win, Darth. If you strike me down, I shall become more powerful than you can possibly imagine.
VADER: You should not have come back.
We have already seen the different ways these two characters wield power. During their duel, Vader sees power as brute force, so he believes he has won against Obi-Wan, but Obi-Wan knows that power is a subtler thing and that his sacrifice will ultimately win the day.
Quote #8
REBEL COMMANDER: The battle station is heavily shielded and carries a firepower greater than half the starfleet. Its defenses are designed around a direct large-scale assault. A small, one-man fighter should be able to penetrate the outer defense.
Star Wars has a sense of individualism running through it. Again, the Empire only sees power in numbers, massive damage, and epic high scores, but the Rebels see that even an individual has the power to stand up to the largest of opponents. It's totally a techno David and Goliath tale.
Quote #9
OBI-WAN: Use the Force, Luke. Let go, Luke.
DARTH VADER: The Force is strong with this one.
OBI-WAN: Luke, trust me.
REBEL: His computer's off. Luke, you switched off your targeting computer! What's wrong?
LUKE: Nothing. I'm all right.
Luke assumes power that he lacked at the film's outset. With no one to help him, he taps the Force to destroy the Death Star and find his place among the universe.