Many in mainstream Christianity believe that the Torah or the Law has been done away with because of misinterpretation's of Scripture penned by Rav Shaul/Paul. Mordecai goes into detail quoting Scripture after Scripture to show, beyond a shadow of a doubt, that the Torah is still valid.
As the reader will see the Torah comes from YHWH not from Moses. Moses was the means that YHWH used to bring the Torah to the people of Israel. As Mordecai shows the Torah is the means that YHWH used to show Israel what was right and wrong in His eyes. Mordecai proves, through Scripture, that the Torah and all that it contains is still valid and is for Israel - especially if we believe that we are part of Israel.