Why is christ's priesthood after the order of melchizedek better than that of the priesthood of aaron?

Aaron's priesthood was tainted with things that God said they shouldn't do, like ripping people off, etc.

Melchizedek, on the other hand, was known as a 'just priest'

this is why Christ's priesthood was after the order of Melchizedek 

hope this helps :D

Thomas edison created the light bulb.