A five-part shape for a 300-word piece, plus the four traps. Short form is harder than long form and this is why.
The shape
300 words[five parts, strictly proportioned]
One concrete image or moment, forty words. The verse, quoted, twenty words. What the verse is doing, sixty words. Where that touches an ordinary Tuesday, a hundred words. One sentence that does not summarise, twenty words. A question or a short prayer, thirty.
The proportions matter more than they look. The commonest failure is spending a hundred and fifty words explaining the verse and thirty on the reader's actual life, which produces a very short Bible lecture.
One movement only
the rule[not one point - one movement]
A devotional moves a reader from one place to one other place. From resentment towards release. From distraction towards attention. If you cannot name the two places, you have a paragraph rather than a devotional.
[write the two places before you write a word: from ____ to ____]
The four traps
avoid these[these are why most devotional writing is interchangeable]
One. The verse used as a springboard and never returned to. If you could delete the verse and the piece still works, it was decoration.
Two. Relentless tidiness. Every day ending in resolution teaches readers that faith has no unresolved days, which they know is false, so they stop believing you.
Three. The generic second person. "Maybe you are feeling overwhelmed today" covers everyone and reaches nobody. One specific situation, honestly described, does more.
Four. Writing about your own faith rather than from it. Readers notice the difference immediately even when they could not name it.
Where the material comes from
the sustainable bit[the real problem after week three]
Keep a running note of small moments through the week and write from those, rather than sitting down to think of something. Five lines a day of what you actually noticed will keep a daily devotional running for a year. Trying to generate insight on demand will not last a month.