The writings of the New Testament were written primarily for the
ordinary Christian believer. A few were to specific people. But on the
whole, it was not for an elite intellectual class within the congregation.
It was only when some leaders introduced the pagan philosophers
and tried to adapt their beliefs to the simple message of the gospel
that the teachings became complicated and hard to understand.
This gave those leaders the authority and power over their
members. There also seems to be a correlation between the demise
of the early Jewish Christians and the newly converted Gentile
believers in accepting ideas that were repulsive to those Jewish
brothers. Eventually, the Gentile members controlled the leadership
roles and forced out the original Jewish members with a vengence
and hatred as evidenced in some of the writings of the early "Church
Fathers."