Then conquer we must , when our cause it is just , And this be our mottoâ '' â In God is our trust . â And the star-spangled banner in triumph shall wave Oâ er the land of the free and the home of the brave . Then conquer we must , when our cause it is just , And this be our motto : â In God is our trust ; â And the star-spangled banner in triumph shall wave Oâ er the land of the free and the home of the brave !