Keeping a written record of one's own conduct is now recommended as a wellbeing practice. It has a much longer history as a religious discipline with a specific method.
The older form was an examination, not a record
Devotional journals were structured around review of the day against a standard, rather than around description of what happened.
The writer worked through a fixed set of questions in a fixed order, which produced entries that look repetitive and were meant to.
Consistency of the questions is what made comparison possible, so a writer could see patterns over months that would be invisible in free description.
It was frequently read by someone else
In many traditions the journal was shown to a director, teacher or confessor at intervals, and was written in the knowledge that it would be seen.
That expectation shaped the writing. It discouraged both concealment and dramatisation, since a reader who knew the writer well would notice either.
The modern private journal loses this entirely, which removes an external check but also removes a reason for the writing to be defensive.
Fixed times made it survive
Rules for religious communities typically specified when the examination happened, usually attached to an existing point in the daily schedule.
Where the practice was left to inclination it lapsed, and manual writers noted this repeatedly and prescribed against it.
The same failure is visible in contemporary journaling, which tends to be intense for a short period and then abandoned, for the same structural reason.
Not all traditions treated introspection as safe
Several bodies of contemplative writing warn about excessive self-scrutiny, describing it as a route to discouragement rather than clarity.
Their remedies include limiting the time spent, ending on something other than fault-finding, and consulting another person when the same difficulty recurs.
Contemporary research on repetitive negative thinking points in a similar direction, distinguishing reflection that resolves from rumination that circulates.
Different purposes need different formats
A gratitude list, a daily log, a structured examination against fixed questions and free writing about a single difficulty are distinct practices with distinct effects and distinct risks.
Blending them into an undifferentiated habit of writing something down each evening loses whatever the individual formats were designed to do, and makes it impossible to tell which element was worth keeping when the practice stops helping.
Anyone using writing to work through persistent distress should treat it as a complement to professional support rather than a replacement, particularly where the same material keeps returning unresolved.