These books are not general knowledge Christian reading, rather they are examples of texts supplementing or replacing the more common Christian canon. Both are established in the sense of having study groups internationally devoted to the texts. Urantia's fourth section is devoted to Jesus, an interesting rereading of our understanding; Oahspe with its autowriting reminds me of some of the New Age Sects. If you run into people following similar paths, these can be very helpful. If you never run into similar groups they can be a confusing slough of a read.
