There is a misconception that the Messiah changed the Law to where the only thing we have to do now is keep "do unto others as we would have them to do unto us".
This is somewhat related to the common objection that all we have to do now is "love".
Here is the verse;
Matthew 7:12 "So whatever you wish that others would do to you, do also to them, for this is the Law and the Prophets"
Notice he is not saying that the only commandment now is do unto others as you would have them do to you, but he is giving a fact about the Law of YHWH.
This will be filled in further later.