Find a local working photographer, ask about the possibility of doing B camera. Candid rolls etc.
Can you direct people?
Can you compose a scene?
Can you control the light?
Can you mix ambient light with additional light?
What if the church minister says in no uncertain terms that flashes are not allowed in his church?
You have a 5D3, whats your B camera?
You have professional indemnity insurance?
You have public liability insurance?
You have theft or damage kit insurance?
Even volunteering for a couple of shoots, are you prepared to make a contribution to the church for their consent to shoot?
You'll have done some training or similar? You'll know your top shutter synch speed? You'll know at which apertures your lenses are soft and at which they are sharp?
I turned video from a hobby into a job. I can have really rewarding days at work, where I come home bouyed by a happy forward thinking client who loves my work, I can also come home shattered, creatively drained by a conservative or pernickity client, who has wandered off brief and is also angling for a discount, or doesn't want to pay for the 7th re-edit which was pretty much the same as the first.
I'm lucky in that I'm a staffer, topping up with the odd repeat freelance work. My staffer bit gives me holiday pay, sick pay, no books to do. The freelance work gives me a little paperwork now and again, if I was a full time freelancer I would be needing to think about chasing the work, invoicing every bit of work, doing full tax audits, not to mention actually doing the work.
I think everybody so far has been very pragmatic. Nobody is saying 'don't do it', more 'know what you are getting into'. It is a different kind of experience shooting for pleasure and shooting on somebody elses time and budget.