I have asked the question myself many times - How important is graphic design to church?
And to some people, talking about graphic design in church might sound like I am 'be-littling' churches to a status of institutions and companies - by talking about branding, website, and all that. Some might find that revolting.. Some might say that a church is a family and we should not be wasting time on looking good and looking cool and looking alternative and indie.
I might agree with you in a way. You might consider graphic design of less importance than soul saving. And the church should focus on the latter instead of thinking about the former.
In the 30's there was a German design movement called Bauhaus who said that Good Design Makes Life Better.
I totally believe in that.
Aesthetics is so important. It sometimes makes all the difference.
For example, a home to a person is a place that brings happy memories, a place that 'feels' like home. Humans are extremely senses-driven beings. They need to 'feel'. Good design contribute to that. A person surrounded by revolting colours doesn't 'feel' quite right, and it affects him mentally. Good design communicates friendliness, acceptance, warmth.
If you spend all weekend (despite the fact that you're very busy all week, lets say) to clean up your house, to make it look good, to make it feel good, to make it clean and nice to live in, and not like a pig sty, you know the importance of good design. Or.. If you prefer a room that's messy with books and cups and clothes littered around, that's the 'branding' you have made for yourself.. That's how you see yourself and wish to convey to your parents or friends who come to your room. You enjoy being there.
Design is a very human activity. It is basic. A church or a family cannot not be into design. They cannot not care. Yes, they might not invest in a graphic designer. That is a matter of economy and budgetting, not a matter of how important design is to them.
Is it less important than soul saving? Well, I don't know. You shouldn't even compare things. Is cleaning up your house more important than inviting people to come over for tea? They all contribute to one thing - building the home.