According to CNN, some French Christian leaders are urging people in that nation not to celebrate Halloween claiming, among other things, that it is Satanist and detracts from the Catholic All Saints Festival. The only problem there is that the Roman Catholic Church originally created All Saints Day to get people to stop celebrating a similar pagan festival for the dead. The whole idea, whether in a secular Halloween party or a religious All Saints Day festival is of pagan origins through and through.
The Halloween experience with costumes, etc., however, is considered largely American, though there are some who think that things like “trick or treating” might have earlier antecedents in British culture (but really, could there possibly be anything more American than dressing up in a costume and demanding that people reward you with candy for it? Ideas like that are what made the United States a great country!)