Christian nationalism is the political-religious movement seeking to fuse United States identity and law with an ultraconservative interpretation of Christianity. In Separation of Church and Hate, the term refers to this belief that the United States should be defined and governed according to a particular interpretation of Christianity, often expressed through the claim that “God intended America to be a Christian nation” (7). This belief stands in direct opposition to Jesus’s teachings on humility, mercy, and peacemaking, which are central to the book’s counterargument. Christian nationalists prioritize cultural and political power over the scriptural commands to serve the marginalized, creating a theology of dominance rather than compassion.

The Levitical Holiness Code refers to the set of priestly laws in the Old Testament book of Leviticus, which are often selectively cited by Christian fundamentalists to police sexuality and social purity. In Separation of Church and Hate, the term refers to these laws as a body of Old Testament rules that are sometimes cited in contemporary religious debates. The most frequently used verse is the prohibition against male-male intercourse, described as an “abomination” (118).

This parable from the Gospel of Matthew describes Jesus’s final judgment of the world’s peoples, where they are separated into “sheep” and “gouts” based on their treatment of the most vulnerable. It functions as an anchor text for the book’s policy-level ethics, establishing a clear, non-negotiable set of social obligations for Christ-followers. The criterion for salvation is not adherence to religious dogma or cultural purity, but tangible acts of compassion.

The New Covenant is the theological concept that Jesus’s life and teachings fulfilled the Mosaic Law, shifting religious and ethical authority from Old Testament ritual codes to his principles of love, mercy, and forgiveness. In the book, the term refers to this shift in emphasis from Old Testament law to Jesus’s teachings. particularly from Leviticus. Fugelsang describes this transition as “Jesus’s software update, from Law 1.0 to Love 1.0” (39), making Christ’s teachings the final interpretive lens for scripture.