I’m curious what you read in it that causes you to think she has an “axe to grind” against the church? It’s been a while since I read it, but if it’s just that Christians don’t come off looking so good in it, then I suggest your evaluation may be a bit hasty.
We (I) created a thread devoted specifically to this book some time ago where we discussed much of this.
Let me just say … you also need to read her sequel: “Children of God” to get the rest of that story. It really all is a single story divided up into those two books. So if you stop with “The Sparrow”, it’s about like reading the first half of Job and never seeing the conclusion.
Now … that said, I’m not guaranteeing satisfaction to you in her second book either, at least not if this was your reaction to her first one. Certainly - I’m not suggesting any ‘happy ending’ or tidy closure as the writer of Job presents, but there is at least some much-valued closure in her second book.
She is not a believer [so far as I recall or would know], but I would contest your impression that she is hostile toward religious belief. While some Christians may like stories where self-identifying Christians are the shining knights and everybody else is a jerk in comparison, that simply doesn’t reflect social realities today (or ever?). If we demanded those sorts of portrayals in our literature, then there is much deep and valuable work lost to us - including much of the Bible itself.
Granted, it certainly isn’t family reading. But literature doesn’t all need to be children-oriented to be religiously-even spiritually perceptive and of value to mature readers. Many passages of the Bible are not “family reading” either.
[Added … I think one of the main things that sets Russell apart from the typically more anti-religious fare of other sci-fi authors is that she puts intelligent dialogue in the mouths of all parties present including the believers! Whereas so many other works (if they mention religion at all) just use it as a whipping boy to pile mockery on. Russell has both believers and unbelievers being real (and intelligent) people with each other; she refuses to straw-man anybody. That may not be a particularly high bar for an author in and of itself, but given its seeming rarity in major sci-fi, her work seems to me leaps ahead of most.]