Hello Lucasz,

Although your query provoked quite a few responses, I suspect you might still be looking for answers. Your example, using be in a somewhat unusual way, was an example of the subjunctive mood. (It sounds as if it has something to do with clinical depression, but it doesn't really.) You are correct in linking it with the French subjonctif. This is why we say things like 'far be it from me,' or 'be that as it may,' or 'if this be treason.' This is the present subjunctive. In the past tense it calls for were in place of was--for example: 'if I were you,' or 'if it weren't for that.' Check out this link for details:
http://www.alt-usage-english.org/subjunctive_supplement.html