A sacrifice is a ritual, in which something is "consumed", i.e. killed, destroyed, eaten or given away. The sacrificed may refer to the giver's person or characteristics, e.g. may a farmer sacrifice cattle, or it may refer to the receiver, i.e. a sacrifice of wine for the god of wine. Or it may refer to a union of the giver and receiver. In all cases the ritual of sacrifice establishes a connection between giver and receiver. That, which is sacrificed, comes to represent both worlds, the present and the supernatural. Source: Gads Religionsleksikon, 1999.
A sacrifice does not need to be a personal offer, but this is often the case in Andersen's oeuvre. Indeed,
What a lively bustle now struck this Viking's castle near the Wild Marsh! A cask of mead was rolled out into the hall, the pile of wood was lighted, and horses were slaughtered. What a feast they were going to have! Priests sprinkled the horses' warm blood over the thralls as a blood offering.
She took delight in splashing her hands about in the blood of horses slaughtered as an offering to the gods. In savage sport, she would bite off the head of the black cock that the priest was about to sacrifice (...)
Early that fall the Viking came home with his booty and captives. Among the prisoners was a young Christian priest, one of those who preached against the northern gods. Of late there had been much talk in hall and bower about the new faith that was spreading up from the south, and for which St. Ansgarius had won converts as far north as Hedeby on the Slie. Even young Helga had heard of this faith in the White Christ, who so loved mankind that he had given His life to save them. But as far as she was concerned, as the saying goes, such talk had come in one ear and gone out the other. Love was a meaningless word to her except during those hours when, behind closed doors, she sat shriveled up as a frog. But the Viking's wife had heard the talk, and she felt strangely moved by the stories that were told about the Son of the one true God.
Back from their raid, the Vikings told about glorious temples of costly hewn stone, raised in honor of Him whose message is one of love. They had brought home with them two massive vessels, artistically wrought in gold, and from these came the scent of strange spices. They were censers, which the Christian priests swung before altars where blood never flowed, but instead the bread and wine were changed into the body and blood of Him who had given Himself for generations yet unborn.