From the Quite Reverend Mightily Oats: "Everywhere I look I see something holy."
His two halves are no longer fighting. They agree that there is good, and there is evil, and the one should be fought for the sake of the other.
What makes this even more heartwarming to an awesome degree is Granny's reaction to Oats's statement. She smiles. Not a nod, smirk, grin, or grimace... a smile!
Mightily Oats's character development in general was really heartwarming. In the beginning he's in such a pitiful state, not knowing what he should believe or what the right thing to do is, desperately clinging to the words of others in hopes of keeping his faith strong. Then it all gets even worse when he learns the vampires wrote parts of his holy books. Now he doesn't even know if his texts are sacred. He wants to be a good person, but he doesn't want to make any kind of judgment because he might be wrong. But Oats comes through in the end, when both parts of him come together as one and he makes a decisive swing of the axe, a swing not even the vampire saw coming. All his life, he had been convinced there was a "Good Oats" telling him to keep his faith and a "Bad Oats" asking him all the inconvenient questions he didn't want to think about. But he finally learns that both Oatses are an important part of him: he needs to be open-minded, he needs to try to understand other points of view, but he also needs to decide what's right and wrong, he needs to have faith in his own judgement. Nobody knows for sure whether they've made the right choices in life, but they need to make them anyway if they want to do any good with it.
The moment when Oats makes a great light. Oats is on the edge of the Despair Event Horizon, feeling as though his prayers are wheeling away into the cold universe with no one to hear them — but then he listens to his own mind. (Much earlier in the book, he'd lamented church's new teachings that Om speaks to the believers from inside their own mind...) And thinking back to the events of Small Gods: however the Church might have grumbled about Mightily's choice to burn his holy book and save a life, Brutha wouldn't even have hesitated.
The lengths to which Hodgesaargh, normally comic relief, went to make sure the baby phoenix would have everything it needed to recover and thrive. There's a man who loves his birds.
A moment at the end when Granny Weatherwax stands in the phoenix's fire and doesn't flinch. It knows and she knows: she's good.
Death gets a small one when he plays fetch with the late Scraps, then snaps his fingers to facilitate Igor's resurrection of the Franken-dog.
Admittedly, helping out was probably the only way he'd ever get his scythe back. Scraps is, after all, a very energetic dog.
The Old Count fondly remembers his previous victims and killers, happily greeting their descendents who genuinely take the praise and give him their respects. He may be a monster, but he's their fair-playing, Affably Evil monster.