Short answer: The God in Wicca is viewed as a multifaceted deity just as the Goddess is viewed with many manifestations. For example, there is a well known chant which names a few of the names associated with his aspects: "Pan, Woden, Baphomet, Cernunnos, Osiris." Another well known God chant is the "Hoof and Horn" chant:
Hoof and Horn, Hoof and HornRead the incredible book, The Witches' God: Lord of the Dance by Janet and Stewart Farrar. It is the companion volume to the Farrar's The Witches' Goddess and describes and explores the Masculine Principle of Divinity.
All that dies shall be reborn
Corn and Grain, Corn and Grain
All that falls shall rise again.*
Longer answer: First, I suppose ought to mention some the God's roles in Wicca as referenced in ritual, prayer, songs, and chants.
In some versions of the Wiccan "Legend of the Decent of the Goddess," the God is described as thus:
In ancient times our Lord, the Horned One, was, as he still is, the Consoler, the Comforter; but men knew him as the Dread Lord of Shadows--lonely, stern, and hard. ..."
This, decription is one of the earlier bits of Wiccan lore published by Gerald Gardner. In this Wiccan liturgical tale, the God is not simply depicted as the "one who plants his seed" within the Mother.
The God is the cthonic Dread Lord of Shadows. He is the God of Death but also the God of Life. In the "Legend of the Decent of the Goddess," he explained "...when men die at the end of time, I give them rest and peace and strength, so that they may return."
The God is frequently also viewed as the God of the Hunt--in this form he appears as both the Hunter (armed with a spear or bow and arrow) and the hunted (a stag with a large set of antlers). He is the Horned One/Antlered One, Mighty Stag! Powerful God, Lord of the Wildwood...As an invocation stated:
"Great God Cernunnos, return to earth again!(A version of the above Cernunnos invocation is found in Janet and Stewart Farrar's Eight Sabbats for Witches and The Witches' Way.)
Come to my call and show thyself to men.
Keeper of Herds, upon the wild hill's way,
Lead the lost from darkness unto day.
Forgotten are the ways of sleep and night
Men seek for them, whose eyes have lost the light.
Open the door, the door which hath no key,
The door of dreams, whereby men come to thee.
O Mighty Stag, O answer unto me!"
He is the God of mortality and immortality. Her brings dreams and opens "the door that has no key."
Likewise, he is the God who rides upon the back of the North Wind and is Horned or Antlered Lord leading the Wild Hunt of the with a pack of black hounds, accompanied by the souls of the dead.
He is a protector and Guardian of the forest and its animals. The Lord of the Trees. The Green Man spewing forth new growth in the wildwood. He is both the Oak King and the Holly King, who rule at different seasons.
For another depiction of the God, there is a fairly well known 20th century ballad, the Hoof and Horn song, which predates the famous "Hoof and Horn" chant*. The lyrics and original tune are by Ian Corrigan. This song is a significant piece of liturgical music for the God:
Hoof and Horn songHe is also the Sun which warms the earth; his kiss of sunlight awakens the sleeping land which causes the budding leaves and wildflowers to open. He is Jack-in-the-Green who leaps up in the spring with the growing crops. He is John Barleycorn** whose beard is the grain.
copyright 1978, lyrics and original tune by Ian Corrigan
reprinted here with author's permissionAs I rode out one morning all on All Hallows' Eve,
I chanced to meet with the Horned One and I asked of him his leave;
His hooves were of the kettle iron, his horns sprang like the bow,
And I was caught up in his pack with the Wild Hunt for to go.We rode and raged through the autumn glade where the earth grew cold and chill,
And everywhere his Wild Hunt rode he worked his icy will;
We rode through village, field and town and shutters drew in fear,
For before us rode the Horned Man, our winter King so dear.And then at last by starlight we came to that wild glade,
Where we trod the ancient circle and the winter spell was laid;
And there I saw my father, ten years and seven dead--
And he did bear the icy spear and wore horns upon his head!But all things come unto an end, so from that place I passed,
And when to Annfwyn I do go, I'll ride with him at last,
The Horned Man will bless us all as sure as you were born!
So raise your cup and sup it up, all hail to Hoof and Horn!!Recorded on: Once Around the Wheel: Modern & Traditional Seasonal Songs a Workshop/Performance by Ian Corrigan and friends, 1987; (suggested retail for CD is $16.00); Ian Corrigan, Association for Consciousness Exploration, 1643 Lee Rd #9, Cleveland Heights, OH 44118, See also "Starwood Memories;" "Ian Corrigan, Live at Starwood."
The Wiccan God can be said to be associated with dance, prophecy, music, ecstasy, craftmanship, smithcraft, wisdom, scholarship, magic, heroism, strength, sacrifice, life and much more.
I would suggest reading the incredible book, The Witches' God: Lord of the Dance by Janet and Stewart Farrar. This was one of the first books to focus on the God, but there are other good ones that have since been published. Search around a bit. Ask other folks, "What is your favorite book on the God?" In the end, you will have to form your own understanding of the Wiccan God, as that is part of comprehending the mystery.
*Ian Corrigan also wrote the famous "Hoof and Horn" chant in 1981.
**"John Barleycorn" is the personified barley grain in English folklore. Barley is a major cereal grain. Important uses include use in making barley bread, a source of fermentable material for beer, and as animal fodder. The grain is also cooked in soups and stews. Barley grains are still commonly made into malt which is ancient method of preparation. Though the remaining folk songs we have date back only to the 16th century, many Neo-Pagans have embraced "John Barleycorn" as one of the names of the God.
"John Barleycorn Must Die"There were three men came out of the West
Their fortunes for to try
And these three men made a solemn vow
John Barleycorn must dieThey've ploughed, they've sewn, they've harrowed him in
Threw clouds upon his head
And these three men made a solemn vow
John Barleycorn was deadThey've let him lie for a very long time
Till the rains from heaven did fall
And little Sir John sprung up his head
And so amazed them allThey've let him stand till midsummer's day
Till he looked both pale and wan
And little Sir John's grown a long, long beard
And so become a manThey've hired men with the scythes so sharp
To cut him off at the knee
They've rolled him and tied him by the way
Serving him most barbarouslyThey've hired men with the sharp pitchforks
Who pricked him to the heart
And the loader he has served him worse than that
For he's bound him to the cartThey've wheeled him around and around the field
Till they came unto a barn
And there they made a solemn oath
On poor John BarleycornThey've hired men with the crab-tree sticks
To cut him skin from bone
And the miller he has served him worse than that
For he's ground him between two stonesAnd little Sir John and the nut-brown bowl
And he's brandy in the glass
And little Sir John and the nut-brown bowl
Proved the strongest man at last"John Barleycorn is a Hero Bold"
John Barleycorn is an hero bold as any in the land,
For ages good his fame has stood and will for ages stand.
The whole wide world respect him no matter friend or foe,
And where they be that makes too free he's sure to lay them low.
Hey, John Barleycorn, ho, John Barleycorn,
Old and young thy praise have sung, John Barleycorn.To see him in his pride of growth his robes are rich and green,
His head is speared with prickly beard fit nigh to serve the Queen.
And when the reaping time comes round and John is stricken down,
He yields his blood for England's good and Englishmen's renown.
Hey, John Barleycorn, ho, John Barleycorn,
Old and young thy praise have sung, John Barleycorn.The Lord in courtly castle and the Squire in stately hall,
The great of name in birth and fame on John for succour call.
He bids the troubled heart rejoice, gives warmth to Nature's cold
Makes weak men strong and old ones young and all men brave and bold.
Hey, John Barleycorn, ho, John Barleycorn,
Old and young thy praise have sung, John Barleycorn.Then shout for great John Barleycorn nor heed the luscious vine,
I have no mind much charm to find in potent draught of wine.
Give me my native nut-brown ale, all other drinks I'll scorn
For true English cheer is English beer, our own John Barleycorn.
Hey, John Barleycorn, ho, John Barleycorn,
Old and young thy praise have sung, John Barleycorn.