Ah, but Jesus saved a woman accused of adultery - Let he who is without sin cast the first stone....Ancient Jewish law has nothing to do with modern Christian law.
Actually what you refer to as "ancient Jewish law" was God's law. God's son Jesus was the fulfillment of the law and with his new covenant, the law became internalized. The law is "written on our hearts and minds" to quote from the book of Hebrews. So we do not adhere to the outward rituals and codes of the Old Testament, but God himself never changes and his justice never changes. Our sins can be forgiven through the sacrifice of Jesus if we have faith in him and demonstrate our faith with our lives.
God's central message from the beginning has always been selfless love and a humble spirit. From Isaiah "The sacrifices of God are a humble spirit and a contrite heart." And in the book of Amos God told men that he despised their religious rituals and assemblies because they were neglecting widows and orphans and taking bribes etc...