Tomlinson is equivocating. He's using "truth" in the sense of truth that doesn't have to be factually true. This is all very nice and fine — I value "story" greatly myself — but it's no more than literary criticism. How do prayers and miracles relate to the kind of "truth" Tomlinson talks about? What about the bodily resurrection of Christ? Is the Easter story no more than "story", containing the kind of "truth" that doesn't have to be actually true? It's all very wishy-washy, and can be made to mean anything anyone fancies it means.
Harry Potter is true, in the sense Tomlinson means. But it's not factually true. If there's a manual explaining how to perform the spells related in JK Rowling's series, I'm not going to believe the spells actually work unless someone can demonstrate that they do.
In the face of a claim that "the meat of Christianity is the teaching of Jesus and his following through on it to the cross" — and the implication that miracles and prayer are side-issues — I followed up with this:
I have no problem with learning life-lessons from literature or myth or anything else we might categorise as "story" — and as far as I'm concerned there's nothing in literary criticism that I need to be skeptical about. I am skeptical about miracles and prayer as portrayed by those who say miracles are more than mere interpreted legend — that actual supernatural events took place — and those who say prayer is actual two-way communication between human and supernatural entities, rather than some kind of objectified meditation. I appreciate that there are many gradations of "Christian" — from the inerrantist literalist fundamentalist to the "sea-of-faith" virtual atheist who thinks Christianity is a-nice-idea-shame-it-isn't-true. Each to their own, I say. The kind of Christian I find annoying, however, is one who espouses the metaphorical view when challenged about miracles and prayer, only to claim intimate knowledge of the mind of God when challenged about scriptural morality in the public square.