The Great Church of the Valley

There are many religions in the Valley. Some of them (like Mitra) were born in the Valley, but have flourished outside of it. Others (such as Darach-Albeth) have their roots outside the Valley, but have flourished within its borders. Orcus certainly falls into this latter category, as his followers within the Valley have not only embraced the demon prince but formed their own chapter of his cult, complete with their own rites and rituals. 
Followers of Orcus can get away with this however, as the cult of Orcus is very much a flexible religion, able to shift to suit the sensibilities of the locals. The form of the church, it's teachings and even the ranks and rites within it are entirely dependent on the rules of the local chapter. The Valley is a breeding ground for chaotic-evil religions, where the harsh environment molds the kind of people willing to don a robe and stab, poison, or necromance their way to an easier life.
Opposing these cults are the copious number of LG and LN religions. Most of them either sprung up in opposition to the forces of evil (Such as the Aerim triplets of Muir, Mitra and Thyr) while others responded to threats, and then took root (such as Sarenrae and Abadar). The single oddity is the church of Telephos.
It is immediately clear that Telephos is an imported religion, many of its most famous tapestries depict adamantium-clad humanoids marching slowly across fields of grain under cold blue skies, carrying their scythes reverently. Adamantium is is almost unattainable in the Valley, and scythes are too closely associated with death to be often associated with a god of the harvest. Nevertheless, Telephos has found a home in the Valley. By a simple measure of square mileage, Telephos is second only to Mitra in the area covered in which they are the primary deity. 
While the cult of Orcus shuffled itself to fit the mood of the Valley, the church of Telephos may as well have been custom-designed to fit the theme and flow of the Valley. Telephos preaches the value of hard work (which is a requirement to farm anything in the Valley's muddy soil), and the gains made from trying to live a nice, ordered life. While Mitra focuses on grand deeds of charity, and Darach-Albirth alludes to a grander, hedonistic approach to the multiverse, the now-dead Arden and Telephos are the only gods to give a value to practicality and not being rained on. 
Telephos also suggests that the gods should not interfere, and that mortals should live their own life (albeit while following a divine code of ethics) and then be judged upon the results. Considering the more interventionist approach taken by the other gods of the Valley (and the occasional catastrophic consequence of those actions), this often met with welcome relief.
On Zelkor's way, the road linking Dejune to Zelkor's Ferry, there is a large barn that has been converted into a church of Telephos. Outside it, adamantium-clad humanoids march slowly across fields of grain under grey skies, reverently carrying their scythes. They do not promise divine favor, nor even better crops. All the offer is the peace in knowing that you will be judged not on your circumstances, nor even on where you end up in life, but rather on whether you tried to follow the laws of Church and land. They also deal with raiders and looters with a violent finality that borders on brutality. Perhaps the ubiquitous nature of the religion is not on the grand gestures it makes, but rather on the small comfort it brings each and every one of its followers.