Keep in mind that as an individual, a Presbyterian and a Protestant, my views of things may not line up exactly with other points of views. Any glaring errors in theology are mine, and if I misrepresent the views of any group, I apologize in advance and request corrections to be submitted to me.
The men to whom Jesus gave His message of salvation were mostly fellow Jews and shared a common religious understanding. His commandments were interpreted through their understanding of Jesus' words and their Jewish heritage. The Jewish way of life was very structured according to interpretations of the law of Moses and the Prophets. Jesus was the Jewish messiah and fulfilled Jewish prophecy, but His message was for more than the Jewish people alone.
47For so the Lord has commanded us, saying, 'I have set you to be a light for the Gentiles, so that you may bring salvation to the ends of the earth.'" 48When the Gentiles heard this, they were glad and praised the word of the Lord; and as many as had been destined for eternal life became believers. 49Thus the word of the Lord spread throughout the region.
Acts 13:47-49
There was a controversy early in the life of the church where some of the disciples believed that followers of Christ should follow the laws of Moses as well, including male circumcision, respect for the sabbath, and kosher food laws. The controversy was relatively brief and was resolved when Peter addressed the other disciples regarding salvation.
7After there had been much debate, Peter stood up and said to them, "My brothers, you know that in the early days God made a choice among you, that I should be the one through whom the Gentiles would hear the message of the good news and become believers. 8And God, who knows the human heart, testified to them by giving them the Holy Spirit, just as he did to us; 9and in cleansing their hearts by faith he has made no distinction between them and us. 10Now therefore why are you putting God to the test by placing on the neck of the disciples a yoke that neither our ancestors nor we have been able to bear? 11On the contrary, we believe that we will be saved through the grace of the Lord Jesus, just as they will."
Acts 15:7-11
Out of this controversy came recommendations to Christian gentiles to restrict certain behaviors.
28For it has seemed good to the Holy Spirit and to us to impose on you no further burden than these essentials: 29that you abstain from what has been sacrificed to idols and from blood and from what is strangled and from fornication. If you keep yourselves from these, you will do well. Farewell."
Acts 15:28-29
There are still invaluable resources in the Old Testament and Jewish tradition, especially since our Savior is the fulfillment of the Messianic prophecies. But becoming a Christian does not mean being forced to adopt the legalistic laws that governed the lives of Jews. Of course, Jewish Christians are free to retain their rich culture and traditions, but since the law of Moses is not a Christian's path to atonement and salvation, it lost much of its traditional importance. This decision seems to allow all Christians to retain their cultural elements that do not conflict with their lives as Christians.