Romans 3:19-20 "Now we know that whatever the Law says, it speaks to those who are under the Law, so that every mouth may be closed and all the world may become accountable to God; because by the works of the Law no flesh will be justified in His sight; for through the Law comes the knowledge of sin."

What was the purpose of the law?  What is the purpose of God's law?  The law is not the means of salvation, not the means whereby we can be seen as righteous before God.  No one will be justified by the law because no one (that is every single person) can every obey the law.  The law is there to let us know of our sin, it is the standard by which we are judged and we all fall short of obeying it.

For those trying to do good to earn favor with God they are under the bondage of the law, in a hopeless effort to please God by their own merits.  We must give up, turn from our sin and turn to Christ who fulfilled the law and is willing to give us His righteousness if we bow down in repentance and faith.