Why can Jesus be called the possessor of heaven and earth?

Les teaches that Genesis 14 gives the title first to the Most High God, when Melchizedek blessed Abram and said, 'Blessed be Abram of the Most High God, possessor of heaven and earth.' Abram then repeats it, lifting his hand unto Jehovah, the Most High God, the possessor of heaven and earth; the all-capitals LORD identifies Jehovah. Jesus had already referred to Himself as the I Am, or the Jehovah of the Old Testament. In Matthew 28:18, Jesus says, 'All power is given unto me in heaven and in earth.' Les explains that this alludes to the title Most High, so He is the possessor of heaven and earth, not only Jehovah but also the Elyon.