Who said "The greatest battles are often fought within oneself."?

This quote is attributed to Thor (The Avengers).

The greatest battles are often fought within oneself. - Thor (The Avengers)

"The greatest battles are often fought within oneself."

Thor (The Avengers) Courage

"I am Thor, god of thunder!"

"You lack the strength to wield such power."

"I have nothing but respect for you, and your work."

"There are no men like me."

"Never let fear stop you from chasing your dreams."

"Courage is being afraid but doing it anyway."

"Sometimes you gotta do what you gotta do."

"Sometimes you have to be the monster to stop the monsters."