Myths of the Norsemen From the Eddas and Sagas
We have already seen how Odin succeeded after many rebuffs in securing the consent of Rinda to their union, and that the son born of this marriage was destined to avenge the death of Balder. The advent of this wondrous infant now took place, and Vali the Avenger, as he was called, entered Asgard on the day of his birth, and on that very same day he slew Hodur with an arrow from a bundle which he seems to have carried for the purpose. Thus the murderer of Balder, unwitting instrument though he was, atoned for the crime with his blood, according to the code of the true Norseman.
The Signification of the Story
The physical explanation of this myth is to be found either in the daily setting of the sun (Balder), which sinks beneath the western waves, driven away by darkness (Hodur), or in the ending of the short Northern summer and the long reign of the winter season. “Balder represents the bright and clear summer, when twilight and daylight kiss each other and go hand in hand in these Northern latitudes.”
“Balder’s pyre, of the sun a mark,
Holy hearth red staineth;
Yet, soon dies its last faint spark,
Darkly then Hoder reigneth.”
Viking Tales of the North (R. B. Anderson).
“His death by Hodur is the victory of darkness over light, the darkness of winter over the light of summer; and the revenge by Vali is the breaking forth of new light after the wintry darkness.”
Loki, the fire, is jealous of Balder, the pure light of heaven, who alone among the Northern gods never fought, but was always ready with words of conciliation and peace. 
“But from thy lips, O Balder, night or day,
Heard no one ever an injurious word
To God or Hero, but thou keptest back
The others, labouring to compose their brawls.”
Balder Dead (Matthew Arnold).
The tears shed by all things for the beloved god are symbolical of the spring thaw, setting in after the hardness and cold of winter, when every tree and twig, and even the stones drip with moisture; Thok (coal) alone shows no sign of tenderness, as she is buried deep within the dark earth and needs not the light of the sun.
“And as in winter, when the frost breaks up,
At winter’s end, before the spring begins,
And a warm west wind blows, and thaw sets in—
After an hour a dripping sound is heard
In all the forests, and the soft-strewn snow
Under the trees is dibbled thick with holes,
And from the boughs the snow loads shuffle down;
And, in fields sloping to the south, dark plots
Of grass peep out amid surrounding snow,
And widen, and the peasant’s heart is glad—
So through the world was heard a dripping noise
Of all things weeping to bring Balder back;
And there fell joy upon the Gods to hear.”
Balder Dead (Matthew Arnold).
From the depths of their underground prison, the sun (Balder) and vegetation (Nanna) try to cheer heaven (Odin) and earth (Frigga) by sending them the ring Draupnir, the emblem of fertility, and the flowery tapestry, symbolical of the carpet of verdure which will again deck the earth and enhance her charms with its beauty.
The ethical signification of the myth is no less beautiful, for Balder and Hodur are symbols of the conflicting forces of good and evil, while Loki impersonates the tempter. 
“But in each human soul we find
That night’s dark Hoder, Balder’s brother blind,
Is born and waxeth strong as he;
For blind is ev’ry evil born, as bear cubs be,
Night is the cloak of evil; but all good
Hath ever clad in shining garments stood.
The busy Loke, tempter from of old,
Still forward treads incessant, and doth hold
The blind one’s murder hand, whose quick-launch’d spear
Pierceth young Balder’s breast, that sun of Valhal’s sphere!”
Viking Tales of the North (R. B. Anderson).
The Worship of Balder
One of the most important festivals was held at the summer solstice, or midsummer’s eve, in honour of Balder the good, for it was considered the anniversary of his death and of his descent into the lower world. On that day, the longest in the year, the people congregated out of doors, made great bonfires, and watched the sun, which in extreme Northern latitudes barely dips beneath the horizon ere it rises upon a new day. From midsummer, the days gradually grow shorter, and the sun’s rays less warm, until the winter solstice, which was called the “Mother night,” as it was the longest night in the year. Midsummer’s eve, once celebrated in honour of Balder, is now called St. John’s day, that saint having entirely supplanted Balder the good. 
Chapter XXII: Loki
The Spirit of Evil
Besides the hideous giant Utgard-Loki, the personification of mischief and evil, whom Thor and his companions visited in Jötun-heim, the ancient Northern nations had another type of sin, whom they called Loki also, and whom we have already seen under many different aspects.
In the beginning, Loki was merely the personification of the hearth fire and of the spirit of life. At first a god, he gradually becomes “god and devil combined,” and ends in being held in general detestation as an exact counterpart of the mediæval Lucifer, the prince of lies, “the originator of deceit, and the back-biter” of the Æsir.
“Odin! dost thou remember
When we in early days
Blended our blood together?
When to taste beer
Thou did’st constantly refuse
Unless to both ’twas offered?”
Sæmund’s Edda (Thorpe’s tr.).
While Thor is the embodiment of Northern activity, Loki represents recreation, and the close companionship early established between these two gods shows very plainly how soon our ancestors realised that both were necessary to the welfare of mankind. Thor is ever busy and ever in earnest, but Loki makes fun of everything, until at last his love of mischief leads him entirely astray, and he loses all love for goodness and becomes utterly selfish and malevolent.
He represents evil in the seductive and seemingly beautiful form in which it parades through the world. Because of this deceptive appearance the gods did not at first avoid him, but treated him as one of themselves in all good-fellowship, taking him with them wherever they went, and admitting him not only to their merry-makings, but also to their council hall, where, unfortunately, they too often listened to his advice.
As we have already seen, Loki played a prominent part in the creation of man, endowing him with the power of motion, and causing the blood to circulate freely through his veins, whereby he was inspired with passions. As personification of fire as well as of mischief, Loki (lightning) is often seen with Thor (thunder), whom he accompanies to Jötun-heim to recover his hammer, to Utgard-Loki’s castle, and to Geirrod’s house. It is he who steals Freya’s necklace and Sif’s hair, and betrays Idun into the power of Thiassi; and although he sometimes gives the gods good advice and affords them real help, it is only to extricate them from some predicament into which he has rashly inveigled them.
Some authorities declare that, instead of making part of the creative trilogy (Odin, Hoenir, and Lodur or Loki), this god originally belonged to a pre-Odinic race of deities, and was the son of the great giant Fornjotnr (Ymir), his brothers being Kari (air) and Hler (water), and his sister Ran, the terrible goddess of the sea. Other mythologists, however, make him the son of the giant Farbauti, who has been identified with Bergelmir, the sole survivor of the deluge, and of Laufeia (leafy isle) or Nal (vessel), his mother, thus stating that his connection with Odin was only that of the Northern oath of good-fellowship.