I don't disagree that he is a type of Christ, a representation of Him from the OT. My only disagreement was with people saying he was Christ. There is no solid evidence for it.
Who he was, as far as we can actually tell, is stated quite clearly.
A priest of the mos high God, to whom Abram payed tithed before tithes were required. Not of the Aaronic priesthood for High Priest, but before, and above it. A representation of what was to come as many things in the OT were.
And then we find that Jesus was what to come. He followed after the neverending order of Melchizedek.