Sullivan Knoth was born in 1933. In 1966, he worked as a shoe salesman in Albuquerque, New Mexico. During these years, Knoth struggled with financial problems and was about to lose his property due to large debts that he could not afford. In desperation, Sullivan turned to a late-night Evangelical radio station for solace, but found no comfort in the voice preaching against the evils of extramarital fornication. As he listened through the preacher's speech, he started hearing something underneath the static, to what he proclaimed to be the voice of God.
The voice of God expressed to Sullivan his dissatisfaction with the world and its Churches, stating that he needed a brave new prophet. The man walked out into the night and saw in the dark sky a vision like that of the Prophet Ezekiel; a terrible, many-faced angelic creature crowned in fire, surrounded by "wheels within wheels". The vision bore a prophecy of Sullivan, who would lead a chosen few to Paradise and save them from eternal damnation before the end of days arrive.
Filled with purpose, Sullivan abandoned all his earthly possessions and started preaching in the streets of Albuquerque. His passion inspired people who were lost in the world and they flocked to him for guidance. Over the passing years, he had dozens of followers, all of whom had donated their possessions to the nascent church dubbed "Testament of the New Ezekiel". They lived communally on a luxury ranch owned by a wealthy woman named Lydia Degan. Sullivan continued to receive messages from God, which he faithfully recorded in a book of verse he called "The Gospel of Knoth".
Sullivan often encouraged all the women of the flock to breed frequently, even donating his own seed to to the cause and personally delivering each baby. The home births gave the New Mexico police the legal authority to crack down on the cult. With a warrant for health and safety violations, police raided Degan's ranch and arrested a dozen cult members. Knoth barely escaped with a handful of followers. All of their assets were seized and the church was in serious danger of falling apart.
Following the guidance of Moses and Abraham, Sullivan climbed a mountain alone to commune with God. He waited on the mountaintop, naked in the wilderness, until God's voice commanded that he sacrifice an eye in exchange for true vision. Knoth unsheathed his knife and slit his left eyeball open. With this act, the veil of reality fell away and Knoth saw with absolute certainty the destiny of his church. He foresaw a town, deep in the wilderness and hidden from civilization, that would be the gateway to the true temple of the Testament of the New Ezekiel. He would call this town Temple Gate and take his followers there to prepare for the end of times.
Knoth warned his flock that the road would be long and the horrors many, and they would all be forced to make difficult sacrifices and impossible choices in the hope of salvation and paradise everlasting. It was the winter of 1969 when Sullivan Knoth and nearly a hundred followers caravanned out into the desert and left their wicked world behind.
In 1971, Knoth and his followers arrived at the place that would later become Temple Gate
While Knoth's presence and influence among Temple Gate is the driving force of the entire story, he is very rarely seen himself. Most of his involvement in the plot is limited to his bellowing, passionate gospel echoing throughout Temple Gate via the intercoms, or his insane disciples referencing said gospel. His voice can be heard as he tortures Lynn Langermann, a captured journalist whose womb he believes houses the Anti-Christ. Later in the game, Lynn's husband Blake breaks into the church and hides in one of the confession booths, watching as Knoth and his followers violently torture a couple for information of Lynn's whereabouts, as she recently escaped. After finding out she's in the mines with the Heretics, a cult which has defected from the Testament, who want the Anti-Christ born, Knoth has the two painlessly put out of their misery.
At the very end of the game, Knoth is encountered one final time by Blake, after Lynn dies from childbirth in the church. Knoth tells Blake that he slaughtered the entire town and that he failed; that it was too late and that the Anti-Christ has already been born, and that the apocalypse is imminent. Bound by his own religion, he won't let himself kill Blake's newborn, and instead begs Blake to kill his own child, before slitting his own throat in sorrow.
Sullivan appears as an overweight, elderly man of medium height with brown eyes, a scar across his left eye and shoulder length receding hairline. His vestments consist of green robes, a stole decorated with his signature crosses and two additional ones around his neck, the larger being modified to resemble the cult's insignia.
- Main article: Sullivan Knoth/Dialogues
- Throughout the demo, pictures of Sullivan Knoth that resemble Christian iconography can be seen in several of the cabins of the village. These pictures are all the same iconographic portrait showing Sullivan with a halo behind him as if to depict him as a saint.