Romans 3:20   Therefore by the deeds of the law no flesh will be justified in His sight, for by the law is the knowledge of sin.
 
In this particular section of the Bible, the divinely inspired writer (the Apostle Paul) wrote this letter to the Romans.  In the above verse, he uses the term “the law” referring to God’s moral law as summarily found in the 10 commandments.  What God is telling us is that by trying to keep the law and be good, we cannot be justified before God. 
 
Verse 23 continues by saying…
For all have sinned and fall short of the glory of God.
 
The reason that we can’t be declared guiltless before a Holy God is because we have all sinned against God.  As the Bible describes, the only way that we as sinners can be made right before a Holy God is through the death of Jesus.  We broke the law and Jesus paid our fine.  We were guilty and deserved hell and He took it for us.
 
So what does God require from us.  God wants us to see our sin and understand that we haven’t kept the deeds of the law.  God wants us to repent of our wickedness and believe in Jesus.  Believe that Jesus truly was God-in-the-flesh and came to earth to die and rose again to give us a new life.