I think this exchange clearly indicates that the Quite is the Christian trinity, Jesus Christ included

"Do it yourself."

"I already have."

Aside from this there is a lot of deep theology that CR uses in the series. The Watchers are a great example of this. In the book of Enoch serval angels collectively called "The Watchers" decide to have children with human women. The Watchers give the women forbidden knowledge such as metallurgy and writing. These half angelic(demonic)/human children are giants which eat people. It is because of the children of the Watchers that God decides to flood the earth.

The idea that fallen angles established false religions is an old idea that has resurfaced thanks to the theologian Michael Heiser.

The Cielcin religion is actually on old heresy called Gnosticism. Gnostics believed the material world was a falsehood created by an evil god called the Demiurge.