Remember, a religion’s doctrine can be interpreted and used differently by anyone. It is not so much the religion that poses a threat, but how people use it. Any other belief system can be just as dangerous to human freedom. Religious figures in government or churches that assert the role of a government are no different than non-religious figures or governments - they simply choose to use religion to justify their violence and control. You might be interested in Rothbard’s work in For A New Liberty which discusses the transition of the State using religion and religious figures to claim authority to other more modern means, like scientific and economic “experts.” As I mentioned before, religion is just one card in the deck that people use to assert their authority over others or justify their behavior. So in that sense it will always pose a danger - but so can any other person’s claim to authority.
But to answer your question: yes! Christian anarchism exists and I think there is a pretty good argument in support of it. Jesus himself was a figure who practiced anarchism in many ways. He opposed the institutionalized, corrupt, and hierarchical nature of government and state religions, and supported mutual aid, charity, and non-violence. He operated outside of the confines of the state (in free association with others) and even challenged it in many ways - and was persecuted and ultimately killed in part because he was seen as such a threat to the status quo.
As for original sin, I think historically this argument may have been used to control and suppress human freedom. (I’m really not well-read in this area, sorry!) However, Christian anarchists argue that God’s will and God’s kingdom, in fact, is human freedom and anarchy. So again, the religious message is open to interpretation and can be used to achieve different means. For a Christian anarchist, it would be wrong to control others or use the threat of force to instill what they think is right or convert people - instead they look to how Jesus shared his message, which is compatible with anarchism.
I think the main concern some anarchists or others would have with Christian anarchism is the idea that they do embrace an ultimate authority. But all anarchists embrace a doctrine to abide by - they all have determined what is right and wrong, and come to the conclusion that anarchism is the best and moral route. Whether someone is led there by their God or any other pursuit is of no concern to me, and is really none of my business.
Diversity and difference in beliefs and lifestyles are not threats to anarchism. In fact, one of the main reasons I support the ideas behind anarchism is because I think it is the only setting where our diversity can thrive peacefully, rather than force us into conflict and oppression.
I haven’t personally read that book, but I’m glad it got you thinking! Thanks for the great question. You might find it worthwhile to ask Bonnie (hipsterlibertarian) about this. I don’t think she is an anarchist, but I’m pretty sure she is a Christian and wound undoubtedly have more insight than I do.