I personally do not think the 10 commandments are null and void. What I do believe is that the ten commandments were not something anyone then nor now could live up to. It is a measure that shows us that we cannot achieve them totally. It is to point out our flaws, I believe it was then also. We have to realize that with out God we cannot achieve perfection. Perfection against the ten commandments is impossible for us without the blood of Jesus. If you break one of the ten you break them all- James 2:10. Jesus added a little more meaning to the ten commandments when He said " it is written do not commit adultery, but I say to you if you lust after a woman you have committed adultery in your heart." Matt 5:28, as well as others. It is only by Jesus can we achieve anything,
Matthew 22:6 “Teacher, which is the great commandment in the Law?” 37 And He said to him, “‘You shall love the Lord your God with all your heart, and with all your soul, and with all your mind.’ 38 This is the great and [o]foremost commandment. 39 The second is like it, ‘You shall love your neighbor as yourself.’ 40 On these two commandments depend the whole Law and the Prophets.”