Chapter 17 starts with John and the Controller discussing why the people are prevented from learning about God. The Controller reads some passages from the old books to explain that God is only needed when people go through tough situations, but in their world, there are no tough situations, therefore God is not needed.
They're old, they're about God hundreds of years ago. Not about God now.
John brings up the argument that by indulging in their pleasures they have degraded themselves. The Controller somewhat agrees with him, considering the other standards in the world. But the Controller doesn't care because, by their standards, everyone is perfectly normal.
Haven't they used his pleasant vices to degrade him?
As a happy, hardworking goods-consuming citizen he's perfect.
At the end of their heated discussion, John declares that he has the right to freedom, religion, fear, and sin. The Controller tells him that he's simply claiming the right to be unhappy and John strongly agrees with the Controller's sarcastic remark. The discussion ends with the Controller shrugging his shoulders and telling John, "you're welcome".