so we still have to use sheep?

I formed this question yesterday as Dr. McGrath spoke about theological models:

Did Dr. McGrath just say that religious models are forced to work with what they are given, as opposed to scientific models which can simply choose the model that best fits?

What I mean is, as much as I like the idea of God as Shepherd, it's a very ancient-nomdic sounding analogy. Not-so-much 2005 Rainforest Cafe and Ikea furniture. Aren't there new analogies which can be true to God but accessible to our age? I can't imagine that Jesus would be using shepherd analogies if he was here using wireless internet. Do we still need to use that model as well?

Two comments that were made:

Maybe he means that insofar as we translate scripture accurately, we have to use the words that those authors used to get across their models and analogies. I would imagine he would agree that in discussion with people, or in talks, that any analogy is fair game. He would probably argue that in serious theological study, interaction and engagement with the traditional scriptural models is required.

and

I think we do have to keep using sheep and shepherd and work on explaining the context... it doesn't mean that we can't use other analogies informally but those analogies will not have the same weight because they are not in Scripture.

but I said back:

I don't mean to say that we would be choosing from thin air a new analogy to explain God. For instace, I wouldn't just say, "God is like a candle" and make inferrences from there. Certiainly someone would have to spend time understanding the *meaning* of the sheep analogies... aspects that can be inferred: sheep can get themselves lost, are in need of guidance and care, etc.

Then we ask: what else in our world easily gets lost, and is need of guidance and care?

I can see where it'd be dangerous, but I'm not sure the sheep analogy can give us *more* information, or is more authoritative than any other analogy that describes orthodox Christian thought.