The holy scriptures are not always easy to read and understand. The Old Testament has many laws that are impossible for us to keep. Consider some of the following laws. Should we apply capital punishment for incorrigible children? (Exodus 21:18-21), for those caught in adultery? And if you will be honest with yourself, this will include a vast number of people today (Leviticus 20:10). What about the false teachers among us (Deuteronomy 13:1-11), should we be stoning them to death?
These laws were established for the Jewish nation. They were not then to be passed onto the Church. The Church was established just over 50 days after Jesus died on the cross. At his death the new covenant came into effect and this is the law Christians are meant to keep today.
Jesus has been described as being of greater worth than Moses, Moses himself tells us there would come another prophet, and we must listen to him. And that prophet was Jesus Christ. When Jesus was baptised in the river by John. God the Father's voice was heard, and he also said "listen to him".
We cannot keep both laws, so we must keep either one or the other. The new laws of Jesus Christ came into effect the moment Jesus died on the cross, and these are the laws all people must keep. Jews and Christians alike. Keeping these laws is the only way to be seen as righteous in the eyes of God.