When one looks at the letters Paul writes, for example, he often starts with the state of affairs that he is addressing and gives a context that he is writing from. From there he goes on to give a doctrinal stance on the situation and in so doing fashions this doctrine around the cross. He then goes on to give application or how this doctrine will look in real life. We see this even in a highly doctrine laden letter such as Romans as well as in a letter such as Galatians.
From the example of Paul I think that preaching should reveal all three aspects for the listener to leave with a correct understating of scripture. If the preaching is wholly about application then the listener, Christian or not, will probably leave trying simply to follow a set of guidelines they were given. If the preaching is simply doctrinal the listener will leave with lots of head knowledge but no idea of how to use that knowledge. I am sure there are those that may argue for either side as being correct but I think that there is a better way.
That better way is to show the passage of scripture in light of the cross and the power of it for the believer. This is not some mystical power but the actual power that Christ delivers by the renewing of the mind and heart for the believer. From the cross we then move to the place the passage holds in a believer’s life from a doctrinal perspective. This can take many forms with some passages being more doctrinal and less applicational while others are the other way around. Once the foundation of doctrine has been laid the message should then move to how this will look in the life of the believer or how the doctrine is to be applied.
There may be some that would see telling people how to live as being legalistic. Now this would be true if we stray from scripture but if we stick to scripture then the claim of legalism is not valid. Paul often told people how they were to live and the eternal consequences of not living as he claimed, by the inspiration of God, they should. The issue here is not about rules and regulations but about how God’s word is displayed through the Christians lives. I agree that there is a danger of people ignoring the fact that we can do nothing apart from Christ but the fact that people may take things wrong is not a reason to avoid the subject. If we are diligent to constantly help people see the hopelessness of trying to do anything apart from the power of Christ we will in the end help them rely more on Christ and less on self and at the same time help those we lead to live God glorifying lives.
If the goal of preaching is to glorify God then it needs to do so in more than just words but in the lives of those we preach to. Application without the cross is legalism but the cross with out works is no better. Actually, can there be the cross without works, not if you read James?