Complex sentence: "Extraordinary" pronouncements of accelerated spiritual advancement were being made by various parties, privately disputed by others, and ranking members of the Order and the Society had publicly declared themselves chosen as "apostles" of the new "messiah".
Split into simpler sentences: Extraordinary pronouncements of accelerated spiritual advancement were being made by various parties, and privately disputed by others. Ranking members of the Order and the Society had publicly declared themselves as having been chosen as "apostles"of the new "messiah".