From Edith Hamilton's Mythology:

Introduction to Norse Mythology

THE WORLD OF NORSE mythology is a strange world. Asgard, the home of the gods, is unlike any other heaven men have dreamed of. No radiancy of joy is in it, no assurance of bliss. It is a grave and solemn place, over which hangs the threat of an inevitable doom. The gods know that a day will come when they will be destroyed. Sometime they will meet their enemies and go down beneath them to defeat and death. Asgard will fall in rains. The cause the forces of good are fighting to defend against the forces of evil hopeless. Nevertheless, the gods will fight for it to the end.

Necessarily the same is true of humanity. If the gods are finally helpless before evil, men and women must be more so. The heroes and heroines of the early stories face disaster. They know that they cannot save themselves, not by any courage or endurance or great deed. Even so, they do not yield. They die resisting. A brave death entitles them--at least the heroes--to a seat in Valhalla, one of the halls in Asgard, but there too they must look forward to final defeat and destruction. In the battle between good and evil they will fight on the side of the gods and die with them.

This is the conception of life which underlies the Norse religion, as somber a conception as the mind of man has ever given birth to. The only sustaining support possible for the human spirit, the one pure unsullied good men can hope to attain, is heroism; and heroism depends on lost causes. The hero can prove what he is only by dying. The power of good is shown not by triumphantly conquering evil, but by continuing to resist evil while facing certain defeat.

Such an attitude toward life seems at first sight fatalistic, but actually the decrees of an inexorable fate played no more part in the Norseman's scheme of existence than predestination did in St. Paul's or in that of his militant Protestant followers, and for precisely the same reason. Although the Norse hero was doomed if he did not yield, he could choose between yielding or dying. The decision was in his own hands. Even more than that. A heroic death, like a martyr's death, is not a defeat, but a triumph. The hero in one of the Norse stories who laughs aloud while his foes cut his heart out of his living flesh shows himself superior to his conquerors. He says to them, in effect, You can do nothing to me be. cause I do not care what you do. They kill him, but he dies undefeated.

This is stern stuff for humanity to live by, as stem in its totally different way as the Sermon on the Mount, but the easy way has never in the long run commanded the allegiance of mankind. Like the early Christians, the Norsemen measured their life by heroic standards. The Christian, however, looked forward to a heaven of eternal joy. The Norseman did not. But it would appear that for unknown centuries, until the Christian missionaries came, heroism was enough.