"They show us it can be done. You can do it, too."
"Tonight I'd like us to study the life of Jesafa the Twice-Shy. Let's think about the answer he gives us to the question, 'When is it persistence and when is it stubbornness?'"
As the logic of this religion goes, the souls who ascend to Chronias must be as close to ideal models of upright living as mortals can manage. To ascend through all the layers of Mount Celestia without merging with the plane is to achieve the ultimate understanding of their chosen spiritual path, often while surviving the growing responsibilities of an advancing archon.
The religion is overseen by the Basilica, a monastery on the first layer of Mount Celestia, where those that have taken the vows to devote their lives to the College hear from Xerona (the gatekeeper) and Zaphkiel (ruler of the Celestial Hebdomad) of the names and features of souls who are permitted to climb the Bridge of al-Sihal. This word comes through proper channels, as these entities obviously have superhuman demands on their time and attention.
Those channels can be temperamental sometimes, too: the archons can be peery about anything that smacks of archon worship. Not only do they exist to serve rather than be served, but it's said some archons worry that too widespread a worship base might even start changing their forms in unexpected ways. They're certainly willing to encourage others to emulate successful emblems of righteousness, though, so at the very least they will pass on the names of those who ascend.
The College's scripture, the Lives of the Ascended, consists of two biographies and a commentary for each soul. The second biography is easier: the priests at the Basilica collect eyewitness and scryed accounts of the deeds an archon performed as they progressed through their chosen path, culminating in the record of that archon's ascension. The first, considerably more difficult, must be compiled through spells such as legend lore, because it is a biography of that soul's mortal life.
This information is the real bottleneck to adding new chapters. It is usually buried deep within the past, forgotten by a petitioner upon their arrival in the afterlife. Managing, through research of true names or intense divination quests, to link a petitioner to a specific mortal life, is a rare achievement, one prized by the Basilica, since it means they can add a chapter to the Lives. Once the life and afterlife of an ascended soul are known, the monks of the Basilica meditate upon it, discuss its import, and write a commentary on the virtues of that life, the principles it upheld and the challenges it faced. This lesson is often written by the Brother who managed to find out the archon's mortal name, so Brothers can be found hunting for clues and memories throughout the Planes.
Chronians are a new, small religion, but they're fervent and proselytizing. Their people are typically driven, disciplined, and honest. They're often found in clumps, traveling in small missionary groups and studying the Lives together. The religion is better known among planars than primes, mostly humans. Interestingly, the religion is moderately popular among orcs, goblins, and other races who turn away from racial deities that dwell on the Lower Planes.
A priest of the Chronian College will, of course, be lawful good. They will often manifest the Celestia Domain, though Law and Good are also common choices, or one of these and a racial domain. Paladins of the College are known, and some of the monks have studied with the fighting schools.
The College is governed by vote of the senior Brothers, with final say over the Lives taken in consultation with all those in residence at the Basilica. Leadership of the College is vested in the Senior Brother, an elected position which is mostly ceremonial. Laureled Brothers are recognized for their skills to oversee various operations, such as the Laureled Researcher, the Laureled Orator, the Laureled Paladin, and the Laureled Writer. The College is supported primarily by donations from the faithful.
Are they leading a campaign where they insist people should say batezu, tanar'ri and Baator instead of devils, demons and the Nine Hells; because such terms are likely to corrupt our impressionable youth? (Think about the children!!!)
[This is the last comment I'll post that turns your well-thought-out idea into a joke]