It depends what your site is about, and how many articles you already have there.
In case it is an old site, authority (150 plus unique articles on it already), you will be fine even if you add no new articles next month.
But if it is a smaller site, or a new one, etc., then it is a different story of course.
Anyway, new article means new visits and improvement of your blog for visitors, that's why you should write some time to time, doesn't matter if it plays role on general SERPs or not.