Tenet

The Protagonist: "To do what I do, I need some idea of the threat we face."
Barbara: "As I understand it, we're trying to prevent World War III."
The Protagonist: "I'm not seeing Armageddon here. Nuclear holocaust?"
Barbara: "No. Something worse."

"Don't try to understand it, feel it."

"'Lying' is the Standard Operational Procedure."

"See you in the beginning."

"That test you passed? Not everybody does. Welcome to the Afterlife."

Andrei Sator: "This is where our worlds collide. How would you like to die?"
The Protagonist: "Old."
Andrei Sator: "You chose the wrong profession."

Neil: "What the hell happened here?"
The Protagonist: "Hasn't happened yet."

"All I have for you is a word: Tenet. It'll open the right doors, some of the wrong ones too."