The "Law" you refer to is the "Jewish" Law, given to the Jews! Among some 600+ laws were some most every nation keeps to this day, in one form or another, that is, the general laws such as prohibition against lying, stealing and murder. Many of the laws were and are cultural and some uniquely Jewish (Kosher).

Since the destruction of the Jewish Temple by Rome in 70 AD, no Jew has been able to keep the whole Law. Compensations have been made for the physical inability to keep the Law.

Slavery, in one form or another, was with Mankind for most all of history and still exists in some places.

Christ came as "King of the Jews" and NOT as anything else. In many instances he would refuse to acknowledge Gentiles although he hinted through out his ministry that he had "sheep of another fold".

Christ summed up the laws in this statement "Thou shalt love the Lord thy God, with all thy heart, and all thy soul, and with all thy mind (Mt 22 37)...Thou shalt love thy neighbor as thyself." (Mt 22:39).

It is the Christian position that Christ was the fulfillment of the Law and the ultimate sacrifices for ALL sin for all time (reference John 3 and Romans 8:1). In Christ ALL are forgiven. It is the height of foolishness to point to an other's sin and not consider your own self a sinner. The Law was not like a net where you could break a few strands and still be upheld. It is a single strand and a break at any point means a fall.

To spare you any tedious theology let me just say this: Whatsoever is not of faith is sin.