“There Will Be Blood” tells the story of an American oilman, Daniel Plainview, who persuades the locals in a California ranching town to let him drill on their land. He also establishes an uneasy rivalry with a preacher, Eli Sunday, and the two men, each selling his own brand of faith, enact the timeless battle between God and Mammon – though who is on what side is not always clear. Manohla Dargis