For years now, it has been a typical part of a Confirmation program or ordinary high school training to expect a certain number of "service hours" from young people. Ideally, it is to introduce them to ways they can continue to go outside of their own comfort zones and help others in an ongoing way. But it can often seem more like a requirement that has to get "checked off" before one can leave the program, as if the service component of life was take care of for good.
Today's readings both talk about service, but in a way that shows that we are always in somebody's service, whether we recognize it or not. St Paul even uses the word "slavery" to talk about this condition we are all in. Yes, all. For Paul, "you are the slaves of the one whom you obey," whether sin, which makes you obey your own passions, or faith, which makes you truly upright. I spotted an interesting example of the first in the news when the latest iPhone was released. Among the people waiting in line (for hours!) to acquire one was a person who said, "It's the newest thing. I have to have it." Isn't "have to" the language of slavery?
You could almost rephrase Paul's thought along these lines: slavery to sin (or any material desire) is a form of compulsion; the obedience of faith is a form of responsiveness. The one is a requirement that seems to brook no dissent; the other is a relationship that calls for personal engagement.
(Pope Benedict has just announced a whole "Year of Faith" to begin next October!)