The concern is this: If you go around telling everyone that they can do nothing to add to their salvation, that their works are meaningless in God's sight, then they won't do any good works!
The concern is admirable. After all, in the 21st century we certainly see the effects of living in a world where no one cares about doing what is righteous according to any objective standard. As in the days of the Judges, everyone does what is right in their own eyes.
The truth, however, is that it is only possible to do good works in the sight of God when you are convinced that you cannot do any good works in the sight of God. It is only when we possess faith (which is a gift from the Holy Spirit) that Christ has done all that is necessary for our salvation that we are even remotely capable of doing anything good.
Allow me to use a rather silly (perhaps even gross) illustration. Let's say that you came home one day and there was a zombie (yes, zombie, an undead creature which feeds off the blood or brains of the living) cleaning your house to perfection and putting your favorite dinner on the table. What would you do? I can tell you what I would do: RUN!
It makes no difference that the zombie is doing something good (i.e. cleaning and cooking). It only matters that they are an undead, that they are not really living. Nothing they could do would allow me to think well of them.
This is how we look to God before faith in Christ. We are the undead. Or rather, we are dead but we do not know it yet. We mull around doing things that we think are good. They certainly look good to us. But from God's perspective it is only a bunch of zombie messing around in His good creation.
It is only when we are made alive by the power of God's Word, it is only when the Spirit creates faith in the promises of Jesus Christ, that we are capable of doing anything good in God's sight. Only when we are resurrected with Christ through baptism can we live, breathe, and do righteous deeds as God intended.
Faith must come before works, and faith is only created by the Gospel.
Only people who are made righteous by faith in Jesus Christ can do anything righteous. Anything else is just dead people pretending to be alive.
[Next: We stand for Saints!]