What makes someone an actual expert on a subject?
The easy and accurate answer is education.
Contrary to what academia wants you to think, this doesn’t have to be the kind of education that comes with a degree. More often than not these days, those certifications mean nothing greater than a significantly sized debt anyway.
There are plenty of people with bachelor’s and master’s degrees who are utterly uninformed on the subject matter they claim to understand. There are acclaimed scientists who invest their entire academic integrity in theory over fact… published historians who are experts on tertiary sources rather than a healthy mix of eye-witness accounts and analysis… and nutritionists steeped in well-researched hokum.
So no. You don’t have to be titled in doctrinal, theological or otherwise religious studies in order to write a Christian nonfiction book.
But you really should know what you’re talking about nonetheless.
Know your Scripture.
If you’re going to be writing a Christian nonfiction book, you really should be a standard studier of the Word. Not just a listener of Christian lectures or a reader of other Christian nonfiction books... but someone who makes a daily habit of opening up the Bible to see what it says.
With that goal in mind, don’t hesitate to look at different translations. Delve into the original language used by the earliest-recorded Christians and Jews who transcribed what God had done and was still going to do. Go deep, not only for your readers’ sake, but for yours as well.
I know we’re all busy. We have our nine to fives, our families and friends, our chores and responsibilities.
Yet none of that means we don’t have time to study God’s Word as Christians – much less Christians who want to write a Christian nonfiction book. Far from it.
Perhaps we need to wake up half an hour earlier in the morning or go to sleep half an hour later. Or maybe our seeming lack of time is a call to cut something out of our too-busy schedules: unnecessary additions, toxic relationships… that sort of thing.
Regardless, spending time with God is what Christianity is supposed to be about. It’s far greater than following a certain set of rules or learning a certain set of sayings. It’s about a relationship with our heavenly Father through his letters to us (i.e., the Bible) and daily conversation.
Now onto the second paragraph of our Writing Challenge above: the part about reading different translations if you’re going to write a Christian nonfiction book. This isn’t to say you have to use those different translations in your manuscript. Only that you should understand the typically small differences in interpretation between them.
This gives you a more open, well-rounded view of the specific subject matter you’re expounding on. Which, come to think of it, is probably why we have not one but four gospel accounts in the Bible.
Each one, recounted by a specific individual, complete with that person’s memories and analysis, allows us readers to have a richer experience of what it was like to physically walk with our Savior.
Somewhat similarly, each biblical translation comes with its own analysis, whether that of an individual or a group. And there’s almost always something to be learned by studying someone else’s opinion.
After all, isn’t that why you want to write a Christian nonfiction book in the first place? So that others can learn from yours?
In that case, it’s best to learn from others first – particularly through God’s Word.