Who said "But only if your cause is just."?

This quote is attributed to Wonder Woman (DCEU).

But only if your cause is just. - Wonder Woman (DCEU)

"But only if your cause is just."

Wonder Woman (DCEU)

"I am the man who can fight a god."

"It has been centuries since I've seen the amazon warrior in action."

"We were created to be an unconquerable force, unstoppable in our purpose."

"Peace requires understanding between all peoples, not just the strong."