Maybe you have to be religious for this one, but it's pretty powerful when Brutha finally finds a good comeback for Om's nihilistic mantra. What the hell is religion about if it isn't about that? It is in fact memorable enough that by the time of Carpe Jugulum it is quoted in the then-current edition of the Book of Om.
Om: "What does it matter [whether or not we kill Vorbis]? In a hundred years, we'll all be dead."
Brutha: "Yes. But here (picks up bowl) and now (throws bowl), we are ALIVE! (CRASH)"
Lu-Tze cheering up Brutha in the Citadel Gardens when he was in the depths of despair and could no longer hear his God.
Just to put things in context, this simple act involves travelling several miles at considerable speed moments after sabotaging the super-powered evil tank just to be able to cheer the hero. It also represents Lu-Tze's most blatant break of the rule of non-intervention, going as far as (kind of) revealing his identity.
Brutha, separated from his tiny, self-centered tortoise god and trapped in the Citadel, storms down to its enormous, immovable Great Gates and starts shouting, "I carried you in the desert! I believed all my life! Just give me this one thing! Give me a sign!" And the Great Gates, thanks to an unrelated (right?) subplot coming to its head at exactly the right moment, swing open.
The Great God Om's first words after recovering his powers and saving Brutha:"I. He is Mine."
This was a Call-Back to the desert, when Om defended Brutha against the various unworshipped small gods there. ("Mine.") Granted, that may have been more survival than anything (as he knew Vorbis, who was also there, would be a poor replacement), but it was still a setup for later events.
Om struggling his way across the land to make it to Brutha before he is killed.
When the god Om, who starts the book completely self-centered, realizes (in a nod to the parable of the good shepherd) that if you want to have thousands of followers you have to care about the individual ones. Asked by a mathematically-challenged god whether one follower is less than fifty-one, he replies, "No. It's the same."
And also, when asked if 50 is less than 51 (read: if a follower was expendable), he answers "A lot less."
Soldiers from opposite sides of a war begin, completely unironically, to help each other in the face of massive natural disaster.
Brutha in the afterlife, deciding to help out the villain of the book.
Made all the more heartwarming when Death tries to warn him off by telling him the kind of man he was helping, to which Brutha simply replies, "I know. He's Vorbis. But I'm me."
In other words, on his death, the first thing Brutha does is rescue someone from hell.
Especially awesome because, as a couple of people note, Vorbis' insidious reign of terror turns everyone he meets into another cruel, greedy copy of himself. Everyone, apparently, but Brutha. And Brutha notes that even he was changed by his encounter with Vorbis; indirectly, Vorbis had changed him from a simple novice to a Prophet and great leader. As the book says, "...he always changed them. That was his triumph."