Would preaching in a church be advantageous for becoming a lecturer? In general, the job of a lecturer (under Australian terminology- I think the terminology is different in America) can be divided up into two main areas of focus: research and teaching, with the latter involving writing up lesson and assessment plans, managing your tutors, delivering lectures to hundreds of students and maybe some tutorials to a few dozen students, marking and moderating assessment, etc. My understanding is that the people hired for these roles are often PhD students or postdocs who have also worked as tutors during their time as PhD students/postdocs - their tutoring gives them teaching experience, while their work as a PhD student or postdoc gives them research experience.

However, because tutorials are generally much smaller than a full lecture, and they would often be following someone else’s lecture notes rather than writing their own, I was wondering if it might be advantageous for someone in those positions to get some experience preaching in a church? Much like a lecturer, a preacher would need to write their own lesson plans, and then deliver the content of those lessons to an audience of hundreds of individuals, in a format fairly similar to that of a university lecture.

As a result, I could see an argument about why delivering Sunday sermons would be advantageous for developing some of the skills a university lecturer would need. However, I’m not certain if it would actually work in your favour if you were to list that experience on your CV.

And so, my Question: would a typical young researcher who is seeking a lecturer role find it advantageous to list experience working as a church preacher? While religious discrimination would of course be illegal, might they find it working against them?
Would preaching at a church help you to become a better lecturer? Almost certainly, as would any similar experience. During the later stages of my PhD I worked in a very popular small museum giving tours and answering questions from the public. I always tell my students that it was the best way for me to hone my speaking abilities: I really learned how to catch attentions and to convey information in a stimulating way. Further, answering hundreds of questions every day (some of which were strange to say the least) prepared me to diplomatically deal with whatever questions are tossed at me after lectures, talks, and conference papers. If preaching does similar for you, you'll see benefits. 

Would putting preaching at a church on your CV help you land an academic job? No, except in the rare case of that being directly relevant to your teaching post: e.g. I had a housemate who did a PhD in religion, taught at a missionary training school, and landed a job at a religious affiliated Uni in the religion department...they would benefit from preaching on their CV. Just as my museum experience was considered "not lecturing", preaching would be the same. You're simply not drawing on the same pedagogical focus, nor are you teaching towards markable learning outcomes.

Edit to answer your final question. No, I truly doubt you would face any discrimination for mentioning preaching on your CV. You would, however, face panel members who would fail to see why such information is relevant on an academic CV. I didn't put my museum job on my academic CV when I was an early career researcher because it wasn't related to my academic work and was, thus, tangential.