More specifically, the Three Eyed Raven is the Lord of Light.
Since I wrote my “Now I am become Death” series on resurrection, the Bran and Bloodraven = R’hllor theory has really caught on, as I think the show is getting closer and closer to making it clear.
In season 7’s “Beyond The Wall” there is yet another conversation between two resurrected characters about why they are alive, what is their purpose, and what the Lord of Light wants from them. This is a theme that is constantly being brought up around resurrected characters and followers of the Lord of Light. That the Lord has a purpose for them, but it’s unclear what that purpose is. Beric believes him and Jon to be soldiers in the Lord of Light’s war.
But in the inside the episode, DnD seemingly let something slip. They compare Benjen to Beric and Jon. They talk about him also waiting to find out what his purpose is. Except Benjen Coldhands wasn’t raised by a Red Priest. He was raised by the Children of the Forest.
This is significant because both the dead raised by the Children of the Forest and the dead raised by the Red Priests are trying to understand what their purpose is as soldiers in the Great War.
Meanwhile, Bran is not a soldier. Bran is not even truly human. Bran is not even Bran anymore. Bran is the Three Eyed Raven, the all seeing time traveling, nemesis of the Night King.
Essentially the show has given us two demi-gods. The Night King, and the Three Eyed Raven. One guides the living, and one guides the dead. The Night King is the Great Other, the Three Eyed Raven is the Lord of Light.
Now, some of you are skeptical because you believe I’m conflating different elements. But in the books this will be far more complex. Bran won’t exactly be the Lord of Light in the books. Magic in the books is more complicated, as it seems to be a force within nature that can be drawn upon in a variety of different ways in a multitude of traditions. The commonality is that in the show and the books Bran will be the force guiding the other characters in the third act of the story.