Christ-centered sermon

Jollyblogger wrote something that resonates within my heart:

Our response to the gospel is always that of repentance and faith, not action. We do not "do" something to apply the gospel, the gospel "does" something to us. Thus I have been very cautious in offering "to-do" lists from texts.

On the other hand I am aware that the Bible is full of commands that demand obedience. Yet, while acknowledging that, I am still left with the Colossians 2:20-23 conundrum.

20 Since you died with Christ to the basic principles of this world, why, as though you still belonged to it, do you submit to its rules: 21 “Do not handle! Do not taste! Do not touch!”? 22 These are all destined to perish with use, because they are based on human commands and teachings. 23 Such regulations indeed have an appearance of wisdom, with their self-imposed worship, their false humility and their harsh treatment of the body, but they lack any value in restraining sensual indulgence.
In other words, telling people what to do and not do has little or no value in getting them to do or not do what they should or shouldn't do. This doesn't mean there aren't things we should and shouldn't do, but do's and don'ts won't get it done.

So how do we resolve this conundrum? T. David Gordon in his book Why Johnny Can't Preach offers some "practical" thoughts:

I know that there are those who are terribly afraid that such Christ-centered preaching will lead to licentiousness; but I categoricaly deny it. I've witnessed with my own eyes the difference between believers who suffer through moralistic preaching and those who experience Christological preaching. The former are never as strong or vibrant in their Christian discipleship as the latter. In theory, we all say we believe, for instance, that good works are the "inevitable" fruit of saving faith. I not only say this; I believe it.

I believe that as people's confidence in Christ goes they do, ordinarily and inevitably, bear fruit that accords with faith. Thus, there is no need for some trade-off here, or some alleged dichotomy suggesting that we need to preach morality if we are to have morality. No; preach Christ and you will have morality. Fill the sails of your hearers' souls with the wind of confidence in the Redeemer, and tey will trust him as their Sanctifier, and long to see his fruit in their lives. Fill their minds and imaginations with a vision of the loveliness and perfection of Christ in his person, and the flock will long to be like him. Impress upon their weak and wavering hearts the utter competence of the mediation of the One who ever lives to make intercession for them, and they will long to serve and comfort others, even as Christ has served and comforted them.