Complex sentence: Hitherto they had been erratic, lukewarm and poorly attended (vagae, tepentes, infrequentesque); those which he instituted were characterized by fasting, prayers, psalms and tears.
Split into simpler sentences: Hitherto they had been erratic, lukewarm, and poorly attended (vagae, tepentes, infrequentesque). Those he instituted were characterized by fasting, prayers, psalms, and tears.