Chapter 7:1-6 of Romans talks about our release from the law because we are now under Christ. Paul uses the analogy of a woman being freed from the bonds of marriage when her husband dies. Likewise, we are dead to the law and alive in Christ.
This passage was really written to those who found (or believed they found) their salvation in obedience to the law. The problem is: we all sin; we all fall short of perfection in adherence to the law. And that disqualifies us from righteousness and holiness and the requirements to enter the presence of the Holy God.
This passage is necessary in understanding that no matter how well we know and understand and follow the law, we can not earn salvation from it. It's really quite comforting to know that we must trust in God and believe His grace is the only thing that can provide salvation from our sins.
Praise God for His Grace.