Here's how I would frame her point of view. If Christianity is not true, then Western society will be absorbed by another more powerful story. And we will become part of that story. So, we ought to be having a conversation about these differing stories.

What I would add is that the true story is ultimately the strongest one. When Christianity was nothing, it took over the Roman empire with zero power and Rome having all the power. This was empowered by the Holy Spirit and embodied by Christians following the law of Christ (loving others as Christ loves us).

“Russell and other activist atheists believed that with the rejection of God we would enter an age of reason and intelligent humanism. But the “God hole” — the void left by the retreat of the church — has merely been filled by a jumble of irrational quasi-religious dogma. The result is a world where modern cults prey on the dislocated masses, offering them spurious reasons for being and action — mostly by engaging in virtue-signalling theatre on behalf of a victimised minority or our supposedly doomed planet. The line often attributed to G.K. Chesterton has turned into a prophecy: “When men choose not to believe in God, they do not thereafter believe in nothing, they then become capable of believing in anything.”’