The Force
Let's be honest: It's difficult to tidily sum up what the Force represents. It's deliberately abstract, and it's shrouded in more mystery than Sia.
In the simplest terms, the Force represents transcendence, which is a fancy way of saying that those who possess the Force aren't restrained by the same limits that the rest of us are. It's how Luke and Darth Vader share a telepathic bond, for example, and are able to sense each other's feelings and physical presence:
DARTH VADER: A small rebel force has penetrated the shield and landed on Endor.
THE EMPEROR: Yes, I know.
DARTH VADER: My son is with them.
THE EMPEROR: Are you sure?
DARTH VADER: I have felt him, my master.
We love our cat, Sir Shmoops-A-Lot, but we can't read his thoughts because we're just ordinary folks who don't have the Force. (If we did, then we'd probably just know he wants to barf in our shoes.)
Because Luke uses the Force for good and Darth Vader and the Emperor use it for evil, the Force also symbolizes morality. It's just like Uncle Ben told Peter Parker: with great power comes great responsibility.
By bestowing all those who have the Force with spiritual clout, the Force, well, forces all those who have it to make important, sometimes life-or-death choices. You can break bad like the Emperor and pump young punks full of Force Lightning on your path to galaxy-wide domination… or you can go the Jedi route like Luke, Yoda, and Obi-Wan and use the Force to forge connections with your community and protect the natural world:
YODA: Remember, a Jedi's strength flows from the Force. But beware: anger, fear, aggression—the Dark Side are they. Once you start down the dark path, forever will it dominate your destiny.
In short, the Force represents an eternal ethical dilemma: self-importance vs. self- sacrifice. Do you use your power to nab the last piece of pizza for yourself, or do you use it to evenly divide that slice between all of your hungry pals? If you're Luke, you split that pepperoni up. If you're the Emperor, you not only eat that last piece, but then you order nine more pizzas for yourself, make everybody else pay for them, and then chow down on all of them in front of those "friends" while you talk with your mouth full about how stupid they are.
With the Force, the choice is yours.