Jeremiah Rigdon was the leader of the Mormons at New Canaan. He is called their "Living Prophet", genuinely considered (by believers) to be the current prophet of God's will on earth. Though Jeremiah is only in his early thirties, the weight of his office can make him seem much older. He has long brown hair, white skin, and dresses simply in a white shirt and blue jeans.
When Jeremiah was in his twenties, he suffered a severe fever from which no one thought he would ever recover. While he was in his fever, he started babbling strange words that no one in New Canaan could understand. After coming out of his fever, he claimed that God had spoken through him and told him that he was the living prophet to replace Judah Black. Many of the Mormons in New Canaan did not believe this. They argued that God did not speak through the living prophets in such a manner. Jeremiah held to his convictions and watched as many of the Canaanites left with Bishop Mordecai. When Mordecai and a few others returned, he did not condemn them or mock their failure, but quietly welcomed them back.
From time to time, Jeremiah suffers fits similar to the one he experienced while in his fever. During these times, he frequently has visions of spirits speaking to him. Among the things he believes God has told him: "Because the men of New Canaan die often in the defense of the town, men are allowed to have multiple wives, that men and women should abstain from the use of drugs and alcohol to ensure clear-headed thought, and that people of all colors, shapes and sizes should be allowed into the New Canaan community if they have pure hearts."
Jeremiah had a vision telling him that the Mormons cannot restore themselves to their former glory until Jericho has been cleansed of sin, so he formed the Hands of God to carry out the deed. Although he'd rather they just submit, give the Mormons the land and move away.
During the day he can be found in the church with Apostle Jude and Apostle Matthew, on Sundays he holds a service that most of the Mormons attend. In the evenings Jeremiah and several brave Mormons journey out to have supper with the refugees on the exterior, followed by talking to the sinners in The Union in an effort to convert them.
Kill Jeremiah: The Hands of God, led by Jeremiah, have recently attacked and burned three of Jericho's caravans. Sheriff O'Connor feels the Hands of God may soon become a bigger threat, so he wants the Prisoner to assassinate Jeremiah if he cannot be convinced to lay off the caravans.
Recover Daniel: If Daniel wasn't taken away from Denver, instead being set free, the only way to take him from New Canaan is by force or by convincing Jeremiah that Daniel is lying about his faith and care for his family.
Leaving Jeremiah in charge means that New Canaan will always be less prosperous than it could be, since he kicks out a lot of talented people that he views as immoral. Removing Jeremiah from power means that the Mormons' morals and ethics quickly get whittled down to the equivalent of all other wasteland cultures, but they become more successful and profitable. If the Prisoner helps Jeremiah with his campaign of cleansing Jericho, innocent citizens and caravaneers will die, and various buildings will be burned down during the attacks on Jericho. However, the Prisoner can forge peace between New Canaan and Jericho, or rather Jeremiah (Persuasion/Hard) and Sheriff O'Connor, which ultimately leads to a favorable ending, even if the water plant isn't optimized.
Doing nothing to influence events at all will ultimately leave the skirmishes becoming increasingly deadly and Jeremiah dooming the Mormons. Most of Jericho will be destroyed and the dream is over for both sides.
After taking up Kill Jeremiah, Jeremiah can be found at the Mormon camp with the Hands of God.
Because of the problems with the water plant, Jeremiah only distributes free water to people living inside the town itself. Unless the Prisoner resolves the problems with the water plant the citizens on the outskirts become increasingly rowdy.
Even Jeremiah has doubts about how "real" his visions are, and if the Prisoner succeeds in diagnosing Revelation John, it instills even more doubt in the people about Jeremiah's visions.
At some point in development Jeremiah's last name was changed from Maxwell to Rigdon which was chosen by Joshua Sawyer to echo Sidney Rigdon, who was one of the individuals involved in the Latter Day Saints "succession crisis."