[...out of blog slumber..]
Tullian Tchividjian has recently posted on "The Pastoral Practicality Of Law-Gospel Theology". I'd encourage you to read it. He describes really helpfully how his (Lutheran) Law-Gospel theology gave him the resources to preach into a horrible pastoral situation of adultery. However, in doing so he used what I think is a really unhelpful bit of Lutheran terminology. He says:
I emphasized and explained to our church was that we are not a one word community (law or gospel) but a two word community (law then gospel).
Surely we know that there is but one Word of God - Jesus Christ revealed in the Bible by the Holy Spirit. However, that word is a sentence. Not two separate words, but a coherent whole that is structured "law BUT Gospel". Or as Paul puts it, "through the law comes knowledge of sin. But now the righteousness of God has been manifested apart from the law" (Romans 3:20-21).
If there were two words, then "the Law" would be the word of God on its own. But, if "the Law" is just part of the word of God, then if you are just preaching "the Law" then you are not preaching the Word of God at all.
So lets have the whole counsel/word of God... lets have Jesus, crucified and risen for us. No mere 'commands and promises', but the one mediator Jesus who comes to us as a command and a promise.