In the first installment of Douluo Continent, "the Pope's line had divine blood/a Godhood Inheritance" primarily referred to Qian Daoliu, Qian Xunji, and Qian Renxue's branch, which possessed the Six-Winged Angel Martial Soul and the Angel God's inheritance.
Bibi Dong, the current Pope, had the Rakshasa God's inheritance. (But she originally had no angel bloodline; after being harmed by Qian Xunji, she had found her own way to the Rakshasa Godhood.)
So the question of "how much they knew" had to be considered on two levels:
Knowing that Spirit Hall's upper ranks/the angel line were powerful, and that the Six-Winged Angel was a top-level martial soul.
Knowing that they truly possessed an "inheritance leading to godhood," involving a divine seat in the Divine Realm.
Within Spirit Hall, the following people explicitly knew that "the angel line carried the Angel God's inheritance": Qian Daoliu was the central insider and guardian of the Angel God's inheritance; Qian Xunji knew that his family carried on the Angel God's lineage; Qian Renxue later undertook the Angel Nine Trials and became fully aware of it.
The enshrined of the Elder Hall/Douluo Hall included Golden Crocodile, Azure Luan, Lion, Guang Ling, Qian Jun, Jiang Mo, and others.
They did not necessarily know every detail about the Divine Realm, but they knew that "the angel line had a divine inheritance, and Qian Renxue could become a god."
Bibi Dong knew that Qian Daoliu's line possessed the Angel God's inheritance, while she herself took the separate path of the Rakshasa God.
The Pope's confidants, such as Chrysanthemum Douluo and Ghost Douluo, knew that Spirit Hall had divine foundations, but did not necessarily know all the inside details of the Angel Nine Trials.
Ordinary Spirit Hall bishops and deacons, such as Su Yuntao, only knew that the Six-Winged Angel