In the world of Fold, the Prime brought forth complex reality; the initial creative force/intelligence/urge in the universe. The Prime was responsible for the great elemental forces, including life, and created the Titans to safeguard the life allowed to grow unguided, protecting them from the Elder Evils that manifested in opposition to the Prime's works. The Titans grew bored of safeguarding and chose to make their own lifeforms, the Elder Titans creating the new Titans, who made the giants. The Elder Titans also sowed the seeds of human evolution, and even made the Gods. Weaving the threads of divine magic into their being, whilst weaving the giants from the threads of the arcane, the gods were intended as shepherds of the elements and aspects of existence. Their rise ended what is known as the Age Before and began the Age of Gods.
The gods helped in the formation of the worlds; creating life and vistas. Their being was suffused with divine essence; an essence that has been known as Godspark. The gods became prolific, some becoming cruel and arrogant, others zealous and egotistical in their 'righteousness', and they were all praised by the humans (their flock) and other races that populated Fold, and their power grew. And then, it happened. Something the gods themselves were powerless to stop; some monstrous malevolence threatened all and in battling it, the gods vanished; their power scattered back into the aetheric winds of existence, their presence, felt by all the mortals, snuffed out. They'd vanquished their foe, but at a terrible cost. Simultaneously, a number of human empires toppled. From the advanced Marru, to the magically adept "Weavers" and many others included.
Now, these causes something of an interesting dilemma, as deities are frequently something of a "linchpin" for D&D, where they act in a manner similar to the gods of Greek myth, walking the mortal world and influencing events. They have conflicts and enmities and grant miraculous powers to their followers... These are the 'Cleric' base class. Clerics are "divine" spellcasters, and pray/meditate every day for an hour to gain their spells for the day, and the powers and spells of two of their deity's "Domains", and are frequently just dismissed in games as 'priests' and 'first aid kits', as one of their primary abilities is being able to sacrifice their spells to heal as and when needed. When you think about it; it's practically abuse of their powers. Priests exist in D&D, but they're not all necessarily Clerics. Clerics should technically be revered as miracle workers; people who the gods have heard and responded to. So where does this leave Clerics in Fold; following the events of Godfall?
One of the concepts put forwards in D&D's Player's Handbook regarding Clerics is that they can follow a philosophy or set of principles instead of a deity or similar (as the Archdevil Dukes of Hell and Demon Princes of the Abyss can be worshiped/petitioned for power). Their devotion still gives them the spells that a cleric can access, as well as access to Cleric Domains. So, where does this power come from? If the deities are so willing to 'share' this magic that anyone who has faith in something can use it, why worship them? If it's a 'universal energy source' deal, what's the point in deities? Cue Godfall; the removal of the deities in "modern Fold", making it a world without Abrahamic Monotheism, or Olympian Polytheism, but rather a slightly more Buddhist/Messianic approach to religion. Religions formed around principles and philosophies; such as "The Order of Illumination" (an organisation primarily concerned with truth and 'enlightenment', as well as rooting out and destroying evil) and "Genesis" (life and birth worshipers), deified individuals from the early days after Godfall such as St. Cuthbert (justice and order) and Wee Jas (dark magic and restful deaths) and even powerful extraplanar beings such as Bahamut and Tiamat (opposing good and evil forebears of the draconic race), Cas (a vengeful fiend-lord) and the Wild Hunt (fey, elven lord of a spectral hunt across the skies on auspicious nights). When the gods vanished, their essence was disseminated across the multiverse; weaving it into the very being of reality, allowing divine powers to be drawn from near-enough anywhere, but the nature of sentient beings leads them to drawing together for support and a sense of community. Hence the existence of the new religions... And the presence of their Clerics and Paladins.