The religious followers of the Lord of Light are called red priests, for their garb (I: 24)
The red priests light fires and sing as the sun sets (I: 24)
The red priests promise that the Lord of Light could hold off a million Dothraki from the walls of the Free Cities (I: 28)
Red priests wear loose red robes (I: 247. II: 116)
"The night is dark and full of terrors" is a phrase from a prayer (II: 17)
R'hllor is the Lord of Light, the Heart of Fire, the God of Flame and Shadow (II: 19)
The red priests speak of Lightbringer, the Red Sword of Heroes, and the hero Azor Ahai, Warrior of Light, Son of Fire. There is a prophecy in ancient books of Asshai that after a long summer an evil, cold darkness shall fall on the world to be combated by Azor Ahai reborn wielding Lightbringer (II: 110)
The red priests have a great temple on Lys and they are always burning one thing or another, calling out to R'hllor (II: 113)
It is said by the red priests that sometimes R'hllor permits his servants to glimpse the future in flames. These visions are said to be never wrong, but those who see them are mortal and can err in their interpretations (II: 117. V: 58)
'Done in the Light of the Lord' is a common way to end letters (II: 117)
The red priesthood sect is numerous and powerful in the Free Cities and the distant east, but there are few who follow R'hllor in the Seven Kingdoms (II: 346)
Red priests wear only red (II: 346)
The Lord of Light is said to have a fiery heart (II: 347)
Followers of the Lord of Light pray before nightfires, beseeching the Lord of Light to bring the dawn (II: 443)
Believers in the Lord of Light seem to believe in a god of darkness as well (II: 454)
Shadows are supposedly the servants of light and the children of fire, creations of the Lord of Light (II: 455)
Followers of R'hllor believe that an eternal battle is being waged between the Lord of Light and the Great Other whose name may not be spoken. He is known as the Lord of Darkness, the Soul of Ice, the God of Night and Terror (III: 288, 803)
R'hllor is called the God of Flame and Shadow (III: 288)
It's said that R'hllor gives his priests the ability to see through falsehoods so that they may battle the servants of the Other (III: 288)
A prayer before a trial by combat, with sentences in parenthesis mark responses from witnesses: "Lord of Light, look down upon us. (Lord of Light, defend us.) Lord of Light, protect us in the darkness. (Lord of Light, shine your face upon us.) Light your flame among us, R'hllor. Show us the truth or falseness of this man. Strike him down if he is guilty, and give strength to his sword if he is true. Lord of Light, give us wisdom. (For the night is dark and full of terrors)" (III: 388)
The death rite administered by the red priests is called the last kiss, as it symbolizes the god's own kiss to send a man on his journey. The priest fills his mouth with fire and breathes the flames inside the person, down his throat to his lungs and heart and soul (III: 444)
"Life is warmth, and warmth is fire, and fire is God's and God's alone" (III: 444)
Some red priests are trained to see things in fires, such as the past, the future, or things present but far away. It takes many years of training to see the shapes beyond the flames, and more years still to learn to tell the shapes of what will be from what may be or what was. Even then it comes hard (III: 489, 490, 706, 707)
Younger children are sometimes given to the Red Temple to become priests. They are taught prayers and spells, and how to look into flames and see visions, though only a few are capable of doing this last (III: 490)
Thoros of Myr was sent to the Seven Kingdoms because of his gift of tongues and his ability to sometimes see visions in flame. It was hoped that he might convert King Aerys, with his love fire, but he preferred his pyromancers and their tricks (III: 490)
It's said that the Lord of Light cherishes the innocent, and that there is no sacrifice more precious (III: 599)
There is a suggestion that kinslaying is accursed in the eyes of R'hllor (III: 600)
The old gods are said to still linger at High Heart, keeping a red priest from looking into his flames and seeing visions (III: 492)
A typical prayer sequence at the nightfire. "Lead us from the darkness, O my Lord. Fill our hearts with fire, so we may walk your shining path . . . R'hllor, your are the light in our eyes, the fire in our hearts, the heat in our loins. Yours is the sun that warms our days, yours the stars that guard us in the dark of night. (Lord of Light, defend us. The night is dark and full of terrors. Lord of Light, protect us.) R'hllor who gave us breath, we thank you. R'hllor who gave us day, we thank you. (We thank you for the sun that warms us. We thank you for the stars that watch us. We thank you for our hearths and for our torches, that keep the savage dark at bay.)" After this follow prayers of thanks and blessing (III: 705, 706)
The prayers at the nightfires go on for more than an hour after they are lit at sunset (III: 706)
Prophecy by fire seems to work best when the visions have to do with danger to the seer (III: 707, 712)
There is a suggestion that the Others are creatures of the God of Night and Terror who wars eternal against R'hllor (III: 868)
There is a prophecy in ancient books of Asshai that after a long summer an evil, cold darkness shall fall on the world to be combated by Azor Ahai reborn wielding Lightbringer (II: 110)
The legend of Azor Ahai in which the hero forged the sword Lightbringer to combat evil. To complete it he sacrificed his wife Nissa Nissa (II: 115)
It is said that at her death Nissa Nissa's cry of agony and ecstasy was said to have made a crack in the face of the moon (II: 115)
A prophecy says that when the red star bleeds and the darkness gathers, Azor Ahai shall be born again amidst smoke and salt to wake dragons out of stone (III: 289)
Azor Ahai reborn is said to be the prince that was promised, prophesised some 5,000 years ago. He is supposed to stand against the Other and if he fails, the world fails with him (III: 711)
It is said that Azor Ahai did not win his war alone (III: 869)