You can start the introduction with your interpretation on courage (what it means to you).
Then complete at least two body paragraphs explaining at least two instances of courage portrayed in the scenes of the book. You will most likely find it as an attribute in the characterization of (at most) one of those who play a role in the book. Incorporate what makes it courageous (you can even refer back to why you, personally, thought it was brave as the reader), and what was the motivation behind it. Include specific quotes to back up your position on conveying how that trait is brought alive in the character, whether through action, dialogue, internal thoughts, etc.
Lastly, sum it all up with a conclusion that ties everything together (both your perspective on courage, and that presented throughout the book).
One reason is that he believes that the colonies have something to fight for.
Where are you going?
The bus isn't stopping!
She isn't wearing a coat
Sam is driving to Manchester today.
What are they talking about?
Vicky is writing an email?
Is it snowing outside?
He's eating an ice cream.