Don Parris's Penguin in the Pew is the only book I know that tries to introduce Linux to ministers and church workers, accordingly is one of the few places that challenges churches that steal proprietary software. Yes, "innocent copying" is theft, and churches aren't often eligible for deep-discounted software.
The book had been available for sale, and the second edition is graciously available for download. The downside? It isn't short. The typesetting and editing don't put the subject (including open source publishing software) in a particularly good light. I think the "non-techie" explanations are still much too technical for most people, and will scare away 99% of ministers who have an honest but passing interest in the subject. The non-theft rationale and the Christian free and open-source software (FOSS) community chapters are interesting, but are so deep into the book that a doubt a lot of people will get to them.
I'll keep my eyes open for a more comfortable read for those with an honest but passing interest . . . and little time to read.