Torah of Messiah

"To those who are without Torah, I become as without Torah, though not being without the Torah of God but under the Torah of Messiah." What is the Torah of Messiah? How can there be a New Torah or different Torah? This teaching from the Second Day of Shavuot draws on the teachings of Lubavitcher Rebbe to unlock the msytery behind Isaiah 51:4, "A Torah will go forth from me" and the New Torah of Messiah, illuminating the meaning of several difficult texts in the apostolic writings and the significance of the New Covenant.