The covenant is written WITHIN the heart and not tied to a historical line

This is the problem the Preterism faces when they define the covenant beginning or ending as a historical line. This is an example of how Preterism seems to focus only on the outward aspects (70ad) of the covenantal line while making secondary the internal aspects (of the heart) to those in Christ. They maintain if Christ has not returned, or the kingdom is not yet established than the new covenant is not yet established. The covenant is written WITHIN the heart and not tied to a historical line. It was not established, but merely is. It is eternal.