During this second read, I noticed something in The Last Battle about how false teachings regarding Aslan were able to enter Narnia and eventually bring about its apocalyptic end.
There are two famous and related descriptions about Aslan in The Lion, the Witch and the Wardrobe, lines that conservative and evangelical Christians have loved to quote. The first description of Aslan occurs when the Pevensie children are first learning about Aslan in the home of Mr. and Mrs. Beaver. Here are the oft-quoted lines:
"Then [Aslan] isn’t safe?" said Lucy."Safe?’ said Mr. Beaver; ‘don’t you hear what Mrs. Beaver tells you? Who said anything about safe? ‘Course he isn’t safe. But he’s good. He’s the King I tell you."
The second famous description of Aslan, also from Mr. Beaver, comes in the final chapter of the book as the children find that Aslan had gone away:
But amid all these rejoicings Aslan himself quietly slipped away. And when the Kings and Queens noticed that he wasn’t there they said nothing about it. For Mr. Beaver had warned them, "He’ll be coming and going" he had said. "One day you’ll see him and another you won’t. He doesn’t like being tied down—and of course he has other countries to attend to. It’s quite all right. He’ll often drop in. Only you mustn’t press him. He’s wild you know. Not like a tame lion."
As I've mentioned, conservative and evangelical Christians love to quote these lines from The Lion, the Witch and the Wardrobe. Aslan "isn't safe," because Aslan "isn't a tame lion."
Conservative and evangelical Christians love these lines because they feel it pushes against the wishy-washy view of God they find among liberal and progressive Christians, where God is always sweet, nice, affirming, docile, gentle, non-judgmental, tolerant, inclusive, kind, and loving. This "love wins" view of God, where God never judges or punishes, is a "tame" God. You see this conservative pushback on the "taming of God" clearly illustrated in a title like Ulrich Lehner's God Is Not Nice, a book where--you guessed it--Lewis' famous lines about Aslan not being safe are cited right out of the gate as the guiding theme of the book.
If you've been around conservative and evangelical Christians, I expect you've also witnessed how "Aslan is not safe" and "Aslan is not a tame lion" have been used to beat back progressive views of God that emphasize God's mercy and grace. But here's the fascinating thing to note from The Last Battle, the final book of the series. The belief that "Aslan is not a tame lion" is the doctrinal entry point which allows the great apostasy to enter Narnia. "Aslan is not a tame lion" is the bit of Narnian faith that allows the anti-Christ figures in The Last Battle to convince the Narnians that Aslan is really Tash, the satan figure of the world.
Let me say it plainly: in The Last Battle the belief that "Aslan is not a tame lion" is the part of Narnian belief and doctrine that allows the faithful to believe that Aslan can act like satan. Believing that "Aslan is not a tame lion" is what convinces the Narnians to worship a satanic Aslan, who they come to call "Tashlan."
This is exactly what happens among conservative and evangelical Christians. Conservative and evangelical Christians use Scripture concerning the wrath and judgment of God--our Biblical versions of "Aslan isn't safe" and "Aslan is not a tame lion"--to describe God as satan, the heresy of saying that Aslan behaves like Tash. That is how anti-Christs in The Last Battle destroyed Narnian faith. They preached sermons to the faithful using book, chapter, and verse of Narnian doctrine--Aslan is not a tame lion--to convince the Narnians that Aslan was Tash.
So, dear readers, beware of the preachers who love to proclaim from their pulpits that "Aslan isn't safe" and that "Aslan is not a tame lion." Beware the preachers of Tash!