Q. 1. What is the heresy of "Melchisedechians?"
A. 1. The Melchisedechians heresy had its beginning with a 9 th century sect of Monarchians who were located in Phrygia. The heresy was founded by Theodotus the banker.
These heretics were teaching that Melchisedech was the incarnation of the of the Logos (Divine Word). They identified Melchisedech with the Holy Ghost.
That assumption may have originated from the private interpretation of the following Bible verses:
"And King Melchizedek of Salem brought out bread and wine; he was priest of God Most High." [Genesis 14:18]
"The Lord has sworn and will not change his mind, 'You are a priest forever according to the order of Melchizedek.'” [Psalm 110:4]
"For it is attested of him (Jesus), 'You are a priest forever, according to the order of Melchizedek.'” [Hebrews 7:17]