Complex sentence: Until these movements in the eighties and nineties came about these messages prevailed in just a few churches, and were not studied in their depth and details as in these times (the eighties and nineties) has been done.
Split into simpler sentences: Until these movements in the eighties and nineties came about these messages prevailed in just a few churches. And were not studied in their dept and details as in these times (the eighties and nineties) has been done.