"The holy ghost"
Translation:Den helige anden
The article is not used in some expressions that are names or almost names – like Vita huset 'The White house' (no one calls it det vita huset) – but there's no hard and fast rule for which word gets treated how as far as I know, you more or less have to learn from case to case where there should be an article or not. I think in this case maybe it has not become established without an article because there's an even older biblical expression, den helige ande, which has been the most common form throughout history.
Please provide examples where Den heliga anden is used more often the Den heliga ande. Specific translation of the Bible; use in Svenska Kyrkan, Pingstkyrkan or similar for example.
In singular instances 'anden' is used, e.g. as a heading. But in the body text 'ande' is far more prominent.
But I digress. I commented on this as a cultural note, not as a fix request.
You're right that den helige ande is used more often than den helige anden. However, we don't always teach the most frequent version, for various reasons. In this case, den helige ande is a very specific form, since normally when we have article + definite adjective + noun, that noun will be in the definite form. This is a beginners' course so we're not trying to teach this exception. Feel free to write something helpful about it in this forum though! (I mean as in helpful for the learners).
In that vein, by the way, den helige anden is a lot less standard than den heliga anden, since the use of -e endings is never obligatory with adjectives.
EDIT: I realise I should clarify, I meant the use of -e to signify male or animate things as opposed to the declension of participles that require it in their plural form.