In 1904, the small Oklahoma town of Canogee is dominated by a ruthless rancher, Bick Justin, and his brutal henchmen, Clint and Steve. Everyone who has attempted to stand up against Justin's rule, including the sheriff, has been killed. Homesteader Mark Bonham, who has accused Justin of rustling his cattle, has been threatened by Justin's men. When Mark visits the general store, Toby, his teenaged son, goes along with him to court the store owner's daughter, Cora Nicklin. Cora's father Dan, who is also the local postmaster, hands Mark a letter from Mark's twin brother Matt, a preacher in Atlanta, Georgia. Later, when Mark reads the letter to his wife Kathryn and sons Toby and Paul, he discovers that Matt has given up his church and is coming to Canogee. This news pleases Kathryn as the town has been without spiritual guidance and leadership since Justin burned down the church and drove out the minister. Sickened by Justin's constant threats, Mark tries to rally the mayor, banker and other townsfolk to oppose the rancher, but is soon disillusioned by their reluctance to become involved. One night, as Clint and Steve try to rustle his horse, Mark awakens, challenges them and is killed. A day or two later, Matt arrives in Canogee by train and upon learning of Mark's murder, conducts his funeral service, preaching against hatred and stating that the town must return to God. As Toby walks away from the grave, unconvinced by his uncle's words, he meets Willy Williams, a bartender and performer of magic in Justin's saloon, who admired Toby's father and wants to pay his respects. Very shortly after his arrival, Matt decides to rebuild the church and enlists Jim Cleery, the local blacksmith, to help him. Nell Landis, the widow of the local doctor killed by Justin, donates the lumber for the building. Meanwhile, Toby, adamant about avenging his father's death, finds his way to Justin's ranch with Willy's help and holds the rancher at gunpoint until Justin throws hot coffee in his eyes and easily overpowers him. When Matt learns of Toby's plan from Kathryn and Cora, he persuades Willy to lead him to the ranch. Meanwhile, the enigmatic Justin denies being involved in the death of Toby's father and, admiring the youth's nerve, invites him to stay for a few days, telling him that he is free to leave when he wishes. After Matt arrives at the ranch, Toby informs him that he intends to stay. Matt then demonstrates his courage by thrashing Steve after the henchman threatens him. Later, when Willy expresses dismay that Toby appears to have joined forces with Justin, Toby tells him that he is working on the inside to try to get proof against the rancher. Some time later, the church building is completed with help from Cleery, Willy and others. When Toby is forced to join Justin's men in robbing a warehouse, Willy tries to stop them from setting fire to the building, but is shot by Clint. Before he dies, Willy tells Cora that he saw Toby with the gunmen. As Cora walks away, Toby approaches her and swears he had nothing to do with the shooting. Perplexed by his actions, Cora challenges him to apologize to the entire town. After Matt demands that the mayor send for state troops, the mayor tells him that his late brother had a similar idea and reminds him of Mark's fate. The next Sunday morning, Matt holds a dedication service for the new church and thanks all who made it possible. While Matt is talking to his new congregation, Justin enters and sits down, but Matt continues to preach against evil men who prey on the innocent. Suddenly, Justin announces that the service is over and gives the worshippers two minutes to leave. Outside, Justin's henchmen pour kerosene on the building while others, including Toby, hold the congregation at gunpoint. Matt warns Justin that he cannot kill the whole town and that there is a greater law than the six gun. As Steve is about to shoot the mayor, Toby shoots Steve and in turn is wounded in the shoulder by Justin. The congregation then stands courageously united against Justin, who faced with this demonstration of faith, suddenly becomes unnerved and rides away with his men. As Cora and Kathryn treat Toby's wound, Matt announces resumption of the service. Matt then tells Cleery that he believes that this is the beginning of a whole new era and that, some day, great cities will rise out of the Oklahoma plains, yet despite man's progress and achievements, he will still need God as they had that day.