And what does it mean?
This is a very good question. There are the words of Jesus in the Gospel of Matthew. He talks about the 2 commandments on which the law and the prophets hang. In simple words these 2 commandments are to love God with all that we have and to love one’s neighbor.
This passage is Jesus’ answer for a man who was asking which was the greatest commandment of all. When Jesus came to this earth he expanded the scope of God’s people from “only Jews” to “everyone”. The Jews are the people who lived by the law. Hence this man has this question - which is the greatest commandment of all. But Jesus summarizes the whole book of law in to 2 commandments. The 2 things on which all law the prophets hang means that the purpose of the whole book of law is to let man love God and love his neighbor. Simply speaking - if a man can keep these 2 commandments it equals to keep the whole book of law.
So when new comers accept Jesus, they donot have to study the whole book of law - but keep these two commandments which covers the whole book of law.
Hope this helps!
Would you share the citation, meaning Book, Chapter and Verses of the scripture you’re talking about for me, @Moses_C?
It is true they do not have to immediately know the whole book of law, but would their repentance and salvation be then empty of doctrine? What I mean is, should not the next step of the newcomer who has repented and believed on Jesus Christ as both their Savior and Lord (not “accepted Jesus” … see James 2:19 NIV “You believe that there is one God. Good! Even the demons believe that—and shudder.” this is a false teaching that crept into the American Christian churches decades ago) be to begin to study the law? In fact, study the Bible in it’s entirety? Otherwise how does the new convert get to know God?
I apologize. I should have been more clear.
What I meant by “law” was the temple worship and sacrifices and all the detailed law from the book of Moses. (Romans:7 4-6)
So Paul explains here that once, you are saved, you are considered dead to the law and now you belong to Christ and serve God in a new way - which is the way of spirit.
There might be a question - if the law dies then does it mean that everyone becomes lawless?
Paul answers this in Romans 12. How should a non-believer in Christ (Be it the Jews/Gentiles) who become a believer by accepting Jesus should live after conversion? -Paul talks about this in Romans 12.
And the concluding argument of it all is in Romans 13:8-10. Paul says that love is the fulfillment of the law. Simply means that if one loves God and loves neighbor (which we fail to do most of the times) he is fulfilling/keeping the law.
If people think love is easier than the book of law, I suggest them to read 1 Corinthians 13 to understand how difficult it is to love.
Hope that clears it all 
I would be more than happy to address in case you have more questions.
Thank you
Thank you @Moses_C. Seems you are an underachiever! You know much and have much to share. I appreciate the citations greatly.
God bless.