This is kind of an adjunct to my post on Krashen's Hypothesis 1: The Acquisition/Learning Distinction.
If one accepts the Acquisition/Learning distinction, then it forces a choice, though perhaps not an exclusive one, on pedagogical issues. Is the student going to aim for language learning or language acquisition? Is a course of language instruction aiming at learning or acquisition?
I want to say that this is a very valid question. It is, for instance, one very valid reason that seminaries might decide (most have decided by default by not considering the question) to teach language learning. If the aim is to produce students who have a competent grasp of Greek (or Hebrew, but I'll keep talking about Greek in particular) grammar, competent enough that they can carry out grammatical analyses of New Testament texts with the use of appropriate tools (computer or paper), then by all means they should construct a curriculum that encourages language learning so that students excel at grammar.
However, let's be clear, only a very small percentage of students will come out of a grammar-focused language learning course, and be able to go on to read Greek with any degree of ease or fluency. And, more often that not I'd wager, that ability has more to do with extra-curricular effort or extended time working on exactly that skill.
If you wanted students to come out of a course of language instruction with an ability to communicate in the language, and this would include reading extended texts in Greek without continual recourse to grammatical analysis or even to lexica, then a course aimed at language acquisition is what you should aim for. Of course, one may ask, "Is there any value in a seminary graduate being able to read biblical texts fluently in their original languages?" To which the answer should be obvious, "Much, in every way."
One doesn't need a technical Greek meta-language to conduct close reading and analysis of Greek texts, if one has acquired Greek rather than learnt it. Doesn't need, I say, but certainly is aided. A mastery of grammar that is additional or complementary to an acquisition of Greek is not to be slighted. Furthermore, grammar can serve to make the language more comprehensible (hypothesis 4), and to aid the Monitor (hypothesis 3).
There is, of course, the option of teaching grammar in the target language. Greek grammar in Greek for instance. This can serve double duty: increasing comprehensible input for acquisition while also teaching for language learning through explicit grammar.
All of which is to say, don't write off grammar. Just recognise grammar for what it is: a technical metalanguage that is very, very useful for analysis of texts, but not an efficient method for language acquisition.