When Christians attempt to live by the Law, we will incur the curse of the Law that no man except for Jesus was able to keep.
As opposed to the blessing, which is grace, the Law is a curse upon all mankind, none of whom can possibly fulfill its requirements. While the Law itself is perfect and holy, those who try to justify themselves before its holy Author bring not His blessing, but His curse upon themselves. The Bible itself tells us what the curse of the Law is: “All who rely on observing the law are under a curse, for it is written: ‘Cursed is everyone who does not continue to do everything written in the Book of the Law.’ Clearly no one is justified before God by the law, because, ‘the righteous will live by faith.’ The law is not based on faith; on the contrary, ‘The man who does these things will live by them.’ Christ redeemed us from the curse of the law by becoming a curse for us, for it is written: ‘Cursed is everyone who is hung on a tree’” (Galatians 3:10–13).
What we must understand from this passage is that the curse is not the Law. The curse is the penalty levied for not keeping the Law. The “Book of the Law” refers to the covenant laws that God made with His people during the time of Moses. The Law can point out where we fail and fall short of God’s will, but it cannot pronounce us righteous; that was not its purpose.