When I use to wait tables for a living, I use to work with a man that would send out a press release every time he did something. If he cleaned the coffee pot or delivered food to a table for you he would make sure you knew about it. He was constantly looking for a pat on the back for the tasks he performed. It was exhausting working with him, as much appreciation as he sought from co-workers.
Many people are like this, a lot of times we assign value to ourselves bases on the good deeds we do. Not only do we want recognition from our peers, many times we act as if the world owes us for our benevolence. Because of this mindset we could go through life relying on our good deeds to get us to heaven unless we know the truth from God's Word.
Paul is stressing to us that all of our good deeds and adherence to the Law is not worth boasting about. Our self-righteousness is excluded and ruled out entirely on the basis of faith. Paul just made a marvelous declaration in the previous verses that the righteousness we need has been provided to us in the person of Jesus Christ. Paul affirms that through faith in His blood we are justified and reconciled to God. So because of faith, boasting in our good deeds is useless, because faith overshadows works much in every way.
Today, be thankful that God does not respond to what we do and how we fall short. Be thankful that we respond to what God did. We don't need pats on the back from our co-workers, our value comes solely through Jesus. Through faith, we are righteous by the His blood. That is a good truth no matter which way you look at it!