If you will, consider this list of issues that illustrate why the UB cannot easily find a cultural home.
First, with regard to Christianity, the UB supports and expands traditional theological tenets such as the loving, personal nature of God and the doctrine of the Eternal Trinity. It generally affirms the ancient ideas of an immortal soul and our creation in the image of God. But it labels other core Christian doctrines as mere human inventions, such as the Pauline doctrine of the atonement (Christ’s substitionary death on the cross in payment for human sin, in order to satisfy God’s demand for justice), the virgin birth of Jesus, the assumption of Mary into heaven, and the idea that Jesus is Second Person of the Trinity. As a result, the UB has been ignored by the vast majority of Protestants and Catholics as well as the Eastern Orthodox Church who have heard of it.
Also in line with traditionalists, the Urantia Revelation rehabilitates the orthodox Christian idea that Jesus was a divine Creator who incarnated on Earth and lived a perfect life as fully man and fully God. (Bear in mind that the UB provides a vastly expanded cosmological and evolutionary context for this description.) Plus it affirms the supernatural nature of Jesus’s resurrection and most of his biblical miracles. But such ideas stymie liberal-modernist Protestants and the so-called postmodern relativists.
While The Urantia Book is ostensibly Christian, it praises selected aspects of Judaism, Buddhism, Hinduism, Islam, and other world religions, which is highly questionable for traditionalists and irrelevant to modernists, but it can be attractive to postmodernists, who are by nature pluralists. And while the text celebrates scientific rationality and actually makes potential contributions to some of the sciences, its revealed cosmology and its relentless critique of materialist reductionism (see for example “The Vulnerability of Materialism” at 195:7) makes the UB verboten for modernist scientists. Because it accepts cosmic evolution and even adds new features to evolutionary theory, the UB utterly leaves behind most traditionalists; but it also advocates for an eternal central universe that is the source, nearly a trillion years ago, of what might be called “mini-big bangs” that initiated space-time evolution, thus alienating modern scientists.
The text affirms in numerous passages the ideals of postmodern tolerance, globalism, and certain forms of relativism, which adds to its appeal to postmodernists. But the UB repels the same people with its almost grandiose meta-narrative of creation and its proclamations about universal existential realities, notably the Eternal Trinity and the “Seven Absolutes of Infinity.” In its most controversial sections it also teaches that the races have different qualities and genetic capacities, which is in particular unacceptable to the egalitarian postmodernists.
The current generation’s rebuff of the Urantia Revelation reminds me of the rejection of Jesus by the Jewish religious leaders and the Roman state. Because of early isolation, misunderstanding, and persecution, the early Christians tended to reify the idea of the crucified and risen Christ. They turned Jesus into a thing apart, almost a fetish, around which they created a personality cult built around the false doctrine of the blood atonement, and subordinated the new religions universal message.
The UB, as well, has suffered rejection, isolation, and even a bit of persecution by its contemporaries. And that’s why so many readers of the book have become as inward-looking as the early Christians were at first. They regard the Urantia text as singular and separate, a unique thing apart (not dissimilar to how Christians have reified the person of Jesus); such readers, without knowing it, turn the UB into the basis of an insular cult. Some believe that the UB stands alone and needs no external cultural referents. And this is a tragic result, because it diverts readers from its profoundly integrative purpose on Earth, in my view. This fetishization of the Urantia Revelation also makes the contents of the book and the Urantia community itself all the more difficult for scholars and researchers to approach it, let alone ordinary new readers.
 See 105:3. “The seven prime relationships within the I AM eternalize as the Seven Absolutes of Infinity. But though we may portray reality origins and infinity differentiation by a sequential narrative, in fact all seven Absolutes are unqualifiedly and co-ordinately eternal.”