Genesis 13-14: Who is Melchizedek and why should I care?

How can Jesus be both our great High Priest and our King? How can he be both David's son and Lord? What does this mean for our lives? The author of Hebrews says this story is "hard to explain" and that it contains "meat for the mature" not "milk" for infants. So get ready to put on your floaties and hop into the deep end of the pool!