You live (I must assume) in a fully democratic country whcih respects the rights of individuals to write and publish (within a given set of reasonable limits) opinions relating to an almost infinite set of matters and ideas. Of such, Abrahamic 'religion' (specifically but not exclusively) has served its tenure through history of being able to reject criticism with the fear of punishment and an endless state of torture and pain in a non-descript 'hell'.
Do you thus reserve the right to 'offend' to the religious status-quo of the pre and post reformation age of Europe, upon where heresy is punishable by the most extreme of punishments? You talk of Pullman's book offering nothing of the "hope or sense of the miraculous" that the bible offers, and I can thus only assume that you have never read the bible (or have at least, like so many, contextualised it to fit whatever spiel you deem fit to support/denounce). My advice is that if you read something that clearly causes friction with your own beliefs, you have a poor mind indeed that is incapable of viewing the state-of-play from the other end.
You (incorrectly) equate atheism (or even just the virtue of scepticism) to "a world that is full of malice, of hatred and no sense of trust or of any real faith", and yet I stand before you as a secular atheist that denounces that which you seem to assume I support.
Most relevent here is about Pullman's Chirst "[being] deluded and easily misled", and yet here you are arguing for that which you have seemingly have no hint of understanding, standing as you are on the pedestal of 'faith' which seems automatically to give you the right to denounce something as "offensive" and thus 'anti-Christian'. The free liberal and tolerant society you live in gives anyone the right to offend you, and if you do not like it, live in a theocracy or totalitarian country (they're effectively synonomous) where your views fit the governmental status quo and thus oppresses those who would not agree (much like Christian Europe in the post-Roman era to the beginnings of the enlightenment).
Kudos to you however that you engaged in the literature which seeks to open your mind and make you question that which you hold so dear and (again I assume but correct me if I am wrong) beleive unqestionably. You are unlike many in that respect (on both sides of the fence) that do not engage but rather 'cast-down' without insight to that which they take aim.
I found many flaws in Pullman's story but the fact that he is able to write with conviction (indirectly here but more so in the Dark Materials trilogy) is testament to the virtue of sceptical thinking and questioning the status quo. Over all I thought the book was a good attempt, but lacked some of the theoretical insight to the duel-characterisation of Jesus/Christ. I would go so far as to call it clever, but agree with you that is not really 'beautiful'.