The word "priest" is just the modern form of the older "presbyter" which can be traced back to the original Greek. You can see this for yourself in any good dictionary with word etymologies (word histories). It will have a history along these lines: Old English: preost, from the older Germanic form represented by Old Saxon, Old High German: prestar, Old Frisian: prestere, from Vulgar (common) Latin: prester (priest), from Late Latin: presbyter ("presbyter, elder"), from the Greek: presbyteros.
Protestant bibles tend to use "elder" here, apparently to obscure the relationship to "priest", but the verb "ordain" [KJV] or "appoint" [NIV, RSV, NASB] makes the connection obvious, nonetheless. Some more modern Protestant Bibles will have "appoint pastors" [e.g., the Living Bible].
Breaking this line of succession is never sanctioned in scripture, nor is assuming pastoral authority for oneself.
