The priesthood as established through the apostles at the Last Supper was very different than what had existed up until that time in the religious practices of Jesus and his generation.
For one, the priesthood was no longer hereditary, no longer the exclusive province of the one tribe of Levites. The exclusivity even went beyond the Jews themselves. Far from basing family on blood, Jesus himself laid out that anyone who follows him is his mother and his sister and his brother. This would have especially come across in his reaching out to Samaritans, who in the end were nothing other than the 'lost' tribes of Israel, the leaderless lower classes of Israelis left behind as the Assyrians scattered their elites to the four corners of the globe in their destruction of the northern kingdom of Israel, based in Samaria.
Jesus brought the Samaritans back into his tent.
The priesthood was no longer an exclusive club based on race, but an inclusive priestly nation, nations even, more primordial than the Levite priesthood, stretching back to the timeless Melchizidek whose own mythological origin has often been seen to a time before Abraham even, to the very beginning of human time.
For another, the priesthood was no longer localized. The prophecy of Jesus fully recognized this as he foresaw that the priests of Levi required the Temple of Jerusalem as the legitimate place of sacrifice, and this was going to be destroyed.
The Temple raised in three days was the Body of Christ, and the temple of sacrifice was as universal as the human body itself. "Do you not know that your bodies are temples?", Paul tells the Corinthians.
The apostleship of the twelve extends the priesthood away from the one tribe, away from exclusivity of Judah and Jerusalem to the fullness of God's people, to all who possess a body even.
A 're-sahendrization' of the religion would really mean a movement away from the sacramental to the sacrificial, to where the Temple in effect would be the exclusive theatre for animal sacrifice.
Of course this never happened historically. In virtually every Christian tradition, the priesthood remains one of the serving of the Body and the Bread, and priestly service being of a sacramental nature, with our bodies and our service and our thoughts and words and deeds being made into our sacred offerings to the Lord.
The main point of contention among Christians has never really been over a return to the Levite priesthood then. The contention is how exclusive is the priesthood to be?
Or, even more pertinently, does the priesthood save us? Is our salvation conditional upon receiving the grace of the sacraments from an exclusively defined ordained priesthood descending from a clearly demarcated line of secession from the original twelve?
"Constantine" has become a watershed event roughly based in history in which the ordained clergy has been seen to have become politicized. Even if this is not an entirely historically accurate picture of who Constantine was, caesaro-papism was a real enough phenomena, and it did become a pressing historic concern whether a Christian's salvation, which is to say, whether his receiving of sacraments through an exclusive, ordained priesthood became contingent on his political affiliation?
This is the conditions that become the reality under caesaro-papism as it has existed in all the major schisms.
On the most basic level, that is the source of the controversy that is with us even today. On the one hand, the need for an authority is still very much there. Truth is important to a religon based on "I am the Truth, the Way, and the Light.
There would be a very big difference, for most of us anyway, in being baptized in the name of the Father, the Son, and Mother Goose, rather than the Trinity of Father Son and Spirit. Nevertheless, does that mean that we need accept the Pope's current environmentalist agenda in order to keep our salvation in standing?
It is a question of authority, and abuse of authority, and the nature of priestly exclusivity that is at the heart of the controversy.
"No salvation outside of the Church" always meant there is no salvation outside of the sacraments of a legitimately ordained, and therefore, an exclusive priesthood.
