Daniel Hill holds a steady part-time job working one or two shifts a week at Starbucks. It's hardly a career-track position, and it's not that he needs the extra cash or battles a secret caffeine addiction.

It's the people.

Purple hair, belly-button rings, tattoos, black-painted fingernails—those people.

For Hill, whose day job is ministering on staff with Willow Creek Community Church's Axis outreach, Starbucks provides a context to build meaningful relationships with postmodern, Gen-Next twentysomethings who are far from God.

"Nothing has been more transforming for me than working at Starbucks," says Hill, "These people matter to me."

But the moonlighting gig isn't a free pass to easy evangelism. His coffee colleagues are like a good cup of triple espresso—plenty of steam, a little bitter, and enough kick to knock you on your backside if you aren't careful.

Exhibit A: "The first day Debbie worked at Starbucks, one of the shift supervisors points at me and asks her, 'Did you hear what his real ...