@prothero,
In the gospels in seems to me the major messages were about:
inner spirituality versus external piety
the primacy of love over legalism
the importance of the spiritual world versus materialism.
Jesus taught to feed the hungry, shelter the poor, heal the sick and comfort the afflicted.
I can not help but think modern churches (especially the Catholic Church) have recreated a faith based on temporal concerns, materiaism, legalism, a politics of holiness and purity and not based on the primary teachings in the gospels.
I can not help but think that a Jesus returning to earth would be displeased with the church supposedly constructed on the basis of his teachings.
In my view Jesus would have many of the same criticisms of the modern church as he had of temple Judaism.