Considering that Christianity came out of Judaism, it would be surprising it didn't pick up a few of the beliefs of the mother belief system. However, there's also no doubt that it picked up a few pagan customs along the way and Christianized them. Easter eggs and Easter bunnies are two good examples.
And, while the U.S. laws are based primarily on English common law, there are a few ideas that came in from other countries. Louisiana, for instance, still has some laws that are based on French law.