One of the most important support roles in progressive churches is the front of house sound mixer. The role is usually filled by volunteers with limited experience and training in audio engineering.
There are numerous resources available to help in the training of such volunteers. Berklee College of Music offers an online course on Church Sound Production and Curt Taipale offers a Church Sound Workshop in a Box. However, most churches would hesitate to make an investment of several hundred dollars to train their volunteers.
I have taught live sound to a number of churches over the years. Most volunteers seem very keen to learn and they often show a remarkable passion for audio.