Never wear your best trousers when you go out to fight for freedom and truth.
A man should never put on his best trousers when he goes out to battle for freedom and truth
You should never wear your best trousers when you go out to fight for freedom and truth
You should never have your best trousers on when you turn out to fight for freedom and truth.
You should never have your best trousers on when you go out to fight for freedom and truth.
One should never put on one's best trousers to go out to battle for freedom and truth.