I don't get it,am i dumb? To me it was just a boring book and Ramon just wasn't interesting. I don't see how the readings from that book at the start mean anything!
No, I don't think it has anything to do with that; rather it is simply lack of reference-points here, I'd say. Joyce was much more known to the sf (as well as other) writers
and fans of that period than he commonly is at present, for one thing. But also, the very passage Ramon is reading poses his problem and, as I noted, quite possibly influences how he views the Lithian situation as well, as it involves a matter of interpretation... all because of the lack of a single punctuation mark (in Joyce's book) which would clarify things. Thus, in Ramon's eyes at least, this mighty feat of the modernists came down to a seemingly substantial but ultimately empty illusion of "the Enemy", much as he views (in very short order) the situation with Lithia.
In other words, his attempt to solve the "case of conscience" with the literary work (incidentally, does anyone know if this is still on the Index Expurgatorius? I don't) may have predisposed him to see the real world problem as yet another example of the same thing, on a grander scale. And, of course, Blish maintains the tension of not knowing whether Ramon is right or not right up through the end of the novel. It is his penance to truly have to rely on his faith and attempt to exorcise that illusion and his own demons of doubt at the same time... but in doing so, he sacrifices not only the scientist in himself, but he must also bear the burden of not ever knowing whether his actions destroyed a truly existing people who were (quite possibly) the universe's only true innocents.
It is not an enviable position. One way, he loses his faith, the very cornerstone of his existence as a priest; the other he betrays his scientific knowledge and training, and denies the first intelligent alien encounter we've had. (IIRC, there are no prior ones mentioned in the novel, yes? It's been a bit....)
Joyce, too, from what I understand both challenged and had an emotionally strong tie (ambivalent though it was) to the older (and the religious) order, so his book serves as a symbol on different levels. Certainly these things come out of in some of his work, such as
Ulysses, itself a book that plays on both the literal and figurative level of signification.