Doing a re read of AFFC and I noticed a detail about how the high septon thinks of himself. He believes he is the human incarnation of the seven gods

"His feet are bare, she saw with dismay. They were hideous as well, hard and horny things, thick with callus. 'You are his high holiness?'"

He answers

"We are"

Referring to himself as we

Later he essentially tells her to bow to him

"So kings and queens must bow before the Seven Who Are One"

Cersei then muses, " is he telling me to kneel"

Cersei inquired about his crown, he then says

"We have no crown, your grace"

This could be seen as him talking about the faith but then shortly after this

Cersei is bid to just follow the high sparrow to somewhere they can speak privately, he says

"If your grace will follow us"

Referring to himself as US

Then just he leads her into the sept proper.

I thought this was interesting to note, that this man essentially considering himself the walking incarnation of the seven gods.