Most of those of Thyatian descest in the duchy belong to the Church of Karameikos. In all, about 25% of the population of Karameikos belongs to the Church of Karameikos, and this segment of the population includes most of the landed nobles and many other political figures.
Many of the members of the Church, especially converts, don't truly understand the intent of the church's philosophy. This philosophy is that no sin committed in the mortal world is so great that it cannot be purified from the spirit by great acts of self sacrifice. Many converts, however, consider it a game with rules to be bent that the church philosophy means they can do anything so long as they subject themselves to the deeds of purification recommended by their church leaders after the fact.
A lesser sin, telling a lie for instance, may require a ceremony of purification no greater than the saying of a few prayers. A moderate sin, such as assaulting someone who did not deserve it, might require a day's vigil and fasting under the watchful eye of a Church cleric. A greater sin, such as murder, may require suffering under secular punishment (i.e. punishment handed down by the courts), but also perfoming some great ceremony of purification, such as risking one's life in an adventure for the Church.
The beliefs held by the Church of Karameikos are as follows
1) The acts of assault, abuse, murder, theft, lying, adultery and living together without the sanctity of matrimony are sins. These sins stain the spirit, and these sins require acts or ceremonies of purification to cleanse the spirit.
2) That an unwillingness on the part of a sinner to purify himself of a sin is itself a sin, punishable by separation from the Church, the eventual result of which is the sinner's spirit becoming too stained ever to be redeemed.
3) The individual's role in the afterlife will be determined by the amount of stain his spirit bears at the time of his death.
4) That it is the responsibility of members of the Church to bring the benefits of Church philosophy to the unbeliever, and to remain present, even in hostile lands, so that the benefits of the Church can be denied to no one who desires them.
Clerics choosing to follow the path of the druid will find plentiful and dangerous forests in Karameikos, that require diligent protection and management.
Clerics belonging to the Church of Karameikos who have highly developed fighting skills may choose to petition for membership to the elite religious order known as the Order of the Griffon, a prestigious society of religious warriors.
Patrons of the church are:
Asterius He represents Peace, Trade and Communication. He is seen as the protector of Karameikos. The Church does not see him as a patron of thievery since this is considered a sin accoding to the church philosophies. His symbol: The Moon.
Ilsundal, the Wise One He represents Nature and Life. Ilsundal is an Elf. His Symbol: A silhouette of the Tree of Life.
Kagyar, the Artisan Creator of the Dwarves. Being associated with the Earth and the Mountains, he represents Steadfastness and Willpower. He is the patron of Artisans. His symbol: Hammer and Chisel crossed in an X.
Valerias, Patroness of Love and Romance She represents Love and Romance. She is also the Healer. Her symbol: A Delicate Rose with especially sharp thorns.
Vanya, Patroness of War and Conquerors She is the Warrior. Chief patron of the Order of the Griffon. She represents Bravery and Honor. Her symbol: A vertical lance with two horizontal swords crossed over it.
Asterius, Valerias and especially Vanya are popular immortals in Thyatis. Kagyar and Ilsundal, also have a great following in the empire due to the presence of the demihuman races. They were possibly included in the hope of comverting the demihumans to the Karameikan faith.
Enemies of the Church are the Demons (Alphaks, Demogorgon and Orcus. Spreaders of evil who will do anything to lead innocents to the path of evil and steal their souls and Thanatos (Immortal of Death and Doom. aka. the Archfiend. Mentioning his name draws his attention and can be your undoing.)
Congratulations, you have now successfully created a Mystaran character!
For further development of this character, consult your Dungeon Master.