In Chapter 1, when the Judge murders Reverend Green by lying to the congregants to whom the Reverend was preaching, he foreshadows the religious tension that is central to the novel in an allusion to Judas and Jesus:
I feel it my duty to inform you that the man holding this revival is an imposter. He holds no papers of divinity from any institution recognized or improvised. He is altogether devoid of the least qualification to the office he has usurped and has only committed to memory a few passages from the good book for the purpose of lending to his fraudulent sermons some faint flavor of the piety he despises.... Oh God, cried the reverend. Lies, lies! He began reading feverishly from his opened bible.... This is him, cried the reverend, sobbing. This is him. The devil. Here he stands.
This scene is the Judge's entrance into the story, and it immediately establishes the Judge as a purveyor of lies and mistruths. Indeed, the Judge later admits that everything he alleges about Reverend Green, from his lack of divine knowledge to his rape of an 11-year-old girl, was entirely made up. The Judge takes the place of the preacher in this scene, standing in front of the pulpit and turning to face the congregation while stealing their hearts and minds with his silver tongue. The Judge, however, preaches a religion of violence, inspiring a man in the crowd to shoot the reverend dead. This act foreshadows the Judge's personal religion, which he later makes explicit in claiming "war is god."
The Judge's supplanting of Reverend Green foreshadows the role of religion in Blood Meridian: the novel will be full of sin and violence. To a certain extent this foreshadows the ultimate ending of the novel, where the Judge—a figure who embodies violence above all else—murders the kid, who in the Judge's eyes represents mercy and innocence (although all members of Glanton's army are incredibly violent figures, the kid included).
The Reverend Green claims the Judge is "the devil," and throughout the novel there are numerous suggestions that this claim is an accurate one. This moment in the story then becomes a twisted perversion of the story of Judas and Jesus, where the Reverend is betrayed and subsequently dies for sins he did not commit, and mankind receives no benefits for him doing so. In fact, the Devil simply continues to propagate more sin throughout the rest of Blood Meridian, ending the novel dancing in celebration of all he accomplished.
The novel begins with the kid's father describing the birth of the kid, which is an allusion to Jesus and the Bible and foreshadows the role of religion in Blood Meridian:
Night of your birth. Thirty-three. The Leonids they were called. God how the stars did fall. I looked for blackness, holes in the heavens. The Dipper stove.
By beginning the novel with a description of the kid's birth, the novel's coming-of-age element is revealed, especially considering the fact that the kid's death occurs at the end of the novel. "Thirty-three" appears to refer to 1833, the year the kid was born. But the diction and syntax are ambiguous, refraining from mentioning the full year. Thus the number itself is highlighted, standing alone in an incomplete sentence. Importantly, 33 is a classic allusion to Christ: Jesus died on the cross in approximately 33 B.C.E., at the age of 33, and elohim, or God, appears 33 times in Genesis's opening chapter. The line "god how the stars did fall" (emphasis added) reinforces this allusion to Jesus and the Bible.
This allusion figuratively establishes the kid, born in '33, as a Christ-like figure, which in turn marks his eventual death as to some extent fated. The rest of the quotation gestures towards the impotency of religious faith, with the stars "falling" out of the sky in the moment of astrological wonder that is a meteor shower and the kid's father looking for "holes in heaven." The presence of sin in the novel, specifically as it relates to the kid, is then foreshadowed by this opening description, with heaven itself seeming to collapse as the kid is born. The stage is also set for the future allusions to religion which come later in the story.