Marx and Engels begin The Communist Manifesto with "A spectre is haunting Europe" because they wanted to warn the bourgeoisie and the elite class that their movement is strong and it is not going to stop until Europe is classless. Literary effect: the movement is mainstream. Political effect: the movement is powerful.
William Bradford basically describes the natives as unfriendly and hostile. He describes them as unfriendly and hostile because when the colonists arrived at the shores, instead of being welcomed with friendly smiles, they were welcomed with deadly arrows.
Their weapons were much more advanced ex. guns, rather than the natives had bows and arrows.