Disclaimer I'm touching base with other suggestions don't go on about these suggestions in this thread some example's: Town Clothes (point 2b), Alliance Halls, Favor, Realms of the gods (concept 1, 2, 3)
An alliance picks a god which they will follow. This gives the alliance certain benefits as given per example below. Every god has it's own set of weaponskins, title, PvE benefits, guild hall or more preferably Alliance Hall (see above link) with one large temple to the god in it.
The statues of the choosen god always have favor in PvE Explorable Areas (with exeption to the one which grants acces to UW). To avoid everybody choosing Grenth or Balthazar the statues in ToA, etc. will not have favor, once every god has it's own realm this can chance (or when favor has become meaningless for PvE).
Guild hall improvement:
Weaponsmith gets a list of inscripable weapons of each kind and linked to each attribute those weapons are normally linked too. For the normal fees they go for at weaponsmiths all over the world.
Clergy Clothes NPC, which sells one set of "Town" clothes for members of the clergy. You need at least one rank in the clergy title before you are elligable to buy these clothes.
New PvP mission:
6 groups of 4 take on each other in a big all out Alliance Battle kind of fight, there are points to cap and capping is key. You get "faction" towards your god, in the same way as you would get normal faction in other PvP missions, per kill, per victory, flawless victory, etc. This translates into points towards a rank in a title for you're god.
Title (Gods name) Clergy:
Account based, each rank attainted will get you one free weapon at your guilds weaponsmith (or, preferably, the one in the Alliance Hall).
Rank 1: (Gods name)'s Protector
Rank 2: (Gods name)'s Saviour
Rank 3: (Gods name)'s Accolyte
Rank 4: (Gods name)'s Priest
Rank 5: (Gods name)'s Bisschop
Rank 6: (Gods name)'s Elder
Rank 7: (Gods name)'s High Priest
Rank 8: Avatar of (Gods name)
Dwayna:
"And when the world rang with the clanging of swords and did fire fall from the skies, Dwayna, goddess of life and air, heard the wailings and pleas of the weak.
And when the rumblings of war did not cease, cameth Her charge Doric, who did prostrate himself at Her feet.
And cast She now a glance upon the war-torn lands and wasted flesh of the fallen, and with tears upon Her cheek did lay her gentle hands upon the prostrate man. Then saith She unto him and all Her charges, Lay down thy weapons, and as I have done unto ye, so ye must do for your brethren. Offer protection to the weak. Give solace and shelter to those who need it. Be ye a salve to the wounded.
For I am your goddess, and I will give blessings to all who follow these teachings."
-- Scriptures of Dwayna: 115 BE
Guild/Alliance hall look:
A hall with wide open space. Lots of blue, white and ligth. Waterworks and waterfalls, maybe balls of light flying around.
PvE Bonus (when displaying title):
You are healed for 1% extra hit points per rank in Dwaynas Clergy title track.
Melandru:
And it was that a tribe of godless humans wandered the land. Where camped did they lay waste, senselessly destroying everything nearby.
And so the tribe set out to find another camp, when suddenly sprouted a wall of thorny branches, which blocked their exit.
Then saith Ewan, leader of the tribe, Know ye our ways. Whosoever does magic in this tribe shall be put to death.
Yet none comes forward. Then, from the earth grows forth a large tree, and unfurling its branches, reveals the upper torso of a woman. Saith She, I am Melandru, Mother of earth and nature. Henceforth I bind ye to these lands. When they suffer, so shall ye suffer.
And as She saith, so was it done. From their limbs sprouted branches, and the blood in their veins was the sap of trees. Then was Ewan and his tribe converted, and became they stewards of nature.
-- Scriptures of Melandru: 48 BE
Guild/Alliance hall look and feel:
A thick jungle, streams, rope bridges. This can be combined with light effects through the roof of leaves.
PvE bonus (when displaying title):
+1 AL against elemental attacks per rank in Melandru's Clergy title track.
Lyssa:
"And it was, that a stranger came to the village of Wren seeking shelter and employment. Though young in years her body was stooped and twisted, her flesh eaten by disease.
"Ye have the mark of plague upon ye, said the citizen named Gallrick. Leave this place lest you sicken our people."
'I've lost my family and my home, cried the desperate woman. Have you no heart?"
Yet each persone, in turn, did look away.
Then from the crowd came a young woman, Sara. She looked upon the woman with pity. "If you need help," said Sara, "I will give it." And Sara did approach the gnarled, bent woman and did offer her a healing hand.
Then the sickend woman pulled from body the robes of plague, revealing Herself to be the goddess Lyssa.
The people of Wren fell to their knees, begging Lyssa's mercy. But lifting Sara gently, saith She, "True beauty is measured not by appearance but by actions and deeds. Many have eyes, but few have seen. Of all here, you saw the beauty behind the illusion. And you alone shall be blessed with My gifts."
-- Scriptures of Lyssa: 45 BE
Guild/Alliance hall look and feel:
The mirror of Lyss is a nice place to look for inspiration for this place. I think there should be a rainbow somewhere.
PvE bonus (when displaying title):
1% extra duration of hexes per rank in Lyssa's Clergy title track.
Balthazar:
For weeks did the battle rage on, and those who had taken up the mantle of war grew weary and their courage began to falter.
Then did Balthazar, god of war and fire, appear to the soldiers, carrying with him a grand sword that did glow with such brilliance it blinded any who looked upon it. When he spoke, His voice was like thunder, and it shook the ground with force.
Then saith he, Lift up thy weapons. For you are My soldiers, and must you be steadfast, strong, and brave of heart. They who neither hesitate nor stumble shall be rewarded. Then shall you have glory. Then shall your deeds be remembered for eternity.
And then did release for His sword a hundred thousand flames, which encircled the soldiers. For this was the fire of courage, and forthwith did they follow the god into battle without fear or hesitation. Thence was the enemy struck down.
-- Scriptures of Balthazar: 48 BE
Guild/Alliance hall look and feel:
Well, look at FoW for inspirtation basicly

PvE bonus (when displaying title):
1% armor penetration per rank in Balthazar's Clergy title track.
Grenth
Came then Desmina, scorned and exiled by her people. And in her misery and wretchedness, did Desmina curse the gods for abandon all who, like her, admired power and ambition.
And asketh she, Where is the god to whom I may give my undying devotion? Where is the God to whom I may beg revenge against those who scorn me?
And rumbled then the earth from far below, and with a terrible groan, split open. Grew then the ground white with frost and ice, and from forth the frozen earth spilled the rotted, skeletal minions of Grenth.
Then did appear the god, and with bony hands outstreched, welcomed the girl into His fold. Saith he, I am your god. Follow where I lead, come whence I call, and the rotted corpses of the dead will be yours to control. And swearing allegiance in life and beyond, did Desmina thence become the god's first follower.
-- Scriptures of Grenth: 48 BE
Guild/Alliance hall look and feel:
Well, look at UW for inspirtation basicly

PvE bonus (when displaying title):
-1 damage reduction from cold damage per rank in Grenth's Clergy title track.
Goddess of Truth
And so it came to pass that Spearmarshal Kormir, hero of all Elona, was pulled into the inky blackness surrounding the God of Secrets. And though her sight had been robbed, her body wracked, and her spirit flayed, she remained resolute.
And so was she joined within the Realm of Torment by fearless allies, and other great heroes, who stood at her side as she sought to thwart Nightfall. Together did they battle through Fear, and Anguish, and Madness, until at last they stood before the face of the imprisoned god; he who had challenged the Five and lost; he who threatened to break the chains placed upon him by the other gods; he who now sought to bring Nightfall to the world: the dark god, Abaddon.
And so did Kormir and her allies engage the dark god in titanic battle. And through her power, and their combined skill and bravery, and the blessings of the Five True Gods, did Abaddon at last face his ultimate defeat.
Yet the power of a god cannot be destroyed, and Kormir, making a choice that only a mortal could make, did take upon herself the mantle of the Goddess of Truth, with all its power and responsibility, all its dominion and duties.
And so by mortal hands did a new immortal enter creation.
-- Scriptures of Kormir, 1075 AE
Guild/Alliance hall look and feel:
The look and feel could be like the ruins in southwestern Lahtena Bog how it would've looked like in it's clory days.
PvE bonus (when displaying title):
Shouts and chants last 1% longer on you per rank in Godess of Truth's Clergy title track.