The passage sets up an interesting contrast between two types of men. What is this contrast, and how is it likely to shape the future of the novel in chapter 9?

I'm not sure which particular passage you are referring to in chapter 9. I think in general we have a self-tormented priest obsessed with thoughts of guilt and impurity. Then you have Chillingworth who is pretty much a sadist getting his kicks out of tormenting the priest.