Do Protestant Churches need a Catechism?

The question seems daft at first, but maybe there is something to it. Of course, there are all kinds of statements of faith out there, but there are quite a few denominations and churches out there which do not adhere to this kind of idea at all.
The idea crossed my screen just yesterday here. From my own limited perspective, the problem is that without such a document or some kind of statement of faith, there is space for misinterpretation, omission, and dismissal. Maybe in a few cases for the better, but all too often for the worse - you find for example plenty of Protestant churches who have no idea of non-Christian religions and how to approach them theologically (I am endeavoring to say that "convert, convert, convert" is not the greatest approach - it might be one, but definitely not one that is well-informed...).