Any fair answer to the question “why are many white supremacists Christian,” starts by carefully defining terms. That includes how to identify a “Christian” but also includes a discussion of what culture, nation, or group we’re speaking of. Talk is cheap; it’s easy to claim to follow a major religion without being especially committed to it, and racial prejudice is used to warp spiritual ideas in every culture.
When ascertaining why many white supremacists claim to be Christians, we must understand self-identification. In Western civilization, including the United States, a substantial proportion of people self-identify as “Christian.” In that context, many white supremacists are “Christian” for the same reason that many musicians are “Christian” and many politicians are “Christian.” When an entire culture identifies as Christian, regardless of other basic beliefs, we can expect to find people from across the social, political, and moral spectrum who call themselves “Christians.”
Racial bias and prejudice have existed in every culture in human history. A person from India might equally ask, “Why are many Indian supremacists Hindus?” Or, in Africa, “Why are many Somalian supremacists Muslims?” The answer, in part, would be the same: because most people in those respective cultures claim a common religious identity. One would expect, statistically, such to be the case.
That leads to the next point: self-identifying is different from self-authenticating. A person can say, “I am a sports fan,” but if he rarely watches or attends games, does not play, and knows little about the sport, his statement has little practical meaning. Identification is not the same as authentication. The self-identified sports fan might attend two or three games a year and wear the logo of a team on his shirt. That doesn’t mean he’s connected to the sport in any consequential way. Some would argue that anyone who says he is a sports fan is a sports fan—but that’s not how the term fan, derived from fanatic, is used in actual conversation.
The same applies to Christianity. Calling oneself a “Christian,” attending church every so often, or having a cross tattoo isn’t proof that one is genuinely connected to the faith. Christianity is not about mere affinity for the Christian religion through a loose cultural connection; it’s about loving and following Christ. It’s not about wearing a label, but imitating a person, Jesus Christ. There may be no mandatory behaviors or attitudes for sports fans, but there are such things for Christians (see John 14:15). A person who operates via racism, arrogance, or prejudice is acting against the principles taught in the Christian faith (Galatians 3:28; James 2:8).
For that reason, self-identifying as a “Christian” while harboring white supremacist attitudes is contradictory at best, and self-deceiving at worst. That’s not to say born-again believers could never hold such attitudes. It is to say that such attitudes are not Christlike; they oppose the very faith the racial supremacist claims to hold. In most nations, racial supremacists rely on cultural traditions and preferences to justify their claims; religion is usually among those traditions. Sadly, that means some in the West hold to racial supremacy while also—paradoxically—claiming to hold to Christianity.