This chapter (5) is discussing revisionism of history and "reality". Pardon the comparison, but like Atlas Shrugged, the book has a particular idea that it is trying to push (without Rand's preachy tones). With Atlas, the world had an obvious absence of children -- there was simply no place for them in Rand's philosophy.
With 1984, there is an absolute absence of religion. However, this is more a feature of the dystopia Orwell is spinning; the freedom to believe in a higher power is antithetical to the notion of Big Brother (in fact, anti to socialism in general), and this is actually the kind of insight that 1984 provokes. I won't be surprised if the topic of religion is addressed at some point.