Who was Melchizedek? 1 - Book of Hebrews (07/14)

What is the importance of the Father appointed Jesus to serve as High Priest in the order of Melchizedek? What made animal sacrifices, temple services and the observances of feasts obsolete? What is the theological significance of the destruction of the temple in A.D. 70? Why is there a new Jerusalem, new Mt. Zion, and new covenant?