Brody and O'Donnell in “Unfinished Business”

Brody

They want you to lose faith. Lose faith in your country, which they say is the devil. In your brother marines, who they say aren't coming for you because you have no military value. In your wife, who they say has got her arms wrapped around someone else.

How do you resist that?

Brody

You can't. Except by believing that those people they want you to renounce, that they're keeping the faith in you and you owe it to them to do the same.

Semper fidelis.