I teach classes as well as retreats. I'm not a "professional", but I'm happy to share what I have learned. Students like handouts and information they can take home and digest. The internet is full of great stuff. Start with About.com (quilting). Samples are a really good idea. And don't be afraid to show them what DOESN'T work. Learning from others mistakes is good. And they know you make mistakes (if you do, hee, hee) and so when they do they won't feel so bad about telling you. Quilting is more than just sewing, so start simple. A nine-patch block or rail fence. I did a full year of just instruction with no hands-on. Like about value, contrast, color, batting, measurements, tesselations, fabric manufacturers, I could go on and on. An equipment list for the students is good. As you know, quilting is an expensive hobby, so let them know what is minimal for getting started. And then encourage them to sign up at JoAnn's and/or Hancock's so they can use coupons for buy stuff on sale or using a coupon. A quilting terms list will help them. We have our own language! Gosh, hope I didn't scare you away. You will love it and adult students are great. If you plan to teach children, that's a whole different story. Plan ahead, relax and enjoy. My first teaching experience was starting a group at my church with about 5 ladies. Seven years later it's still going strong. Hope that helps.
As for your priest, let him do the job God has assigned him and you do as God leads you.