Hi Folks,
We have to study the etiology of the word "clergy" to understand how a pseudo ruling class arose in the church. I use the term "pseudo" to distinguish the ruling class from those gifted with a legitimate "doma" gift of rule from God.
We get the word "clergy" or "cleric" from the Greek word kleros. The word is attached to a grant of inheritance from an estate.
In scripture, you can find it at Colossians 1:12 "..giving thanks to the Father who has qualified us to be partakers of the inheritance of the saints in the light." This is an exhortation to "..the saints and faithful brethren in Christ who are in Colosse...". Therefore, the kleros, or clergy, include all of those who are in Christ.
It was not until after 325 A.D., when the church fathers exchanged their heavenly inheritance for one vested in Rome, that we see the division of the clergy and laity (laity is not found in scripture). This was done to create a ruling class, in the church, that mirrored that of the Roman government. Instead of grants of rule given through the doma gifts by God, the Roman church established leadership offices that men could inhabit if they met criteria outlined by the state. For example, in the church, one is recognized as a pastor if they posses the gift given by God. In the Roman way, one can become a pastor by completing seminary and by demonstrating compliance to a certain pedagogy.