Complex sentence: In the aftermath of the plague, many more Days of Obligation were declared by the church, days when all people were supposed to go to mass, and "to abstain from those works and affairs which hinder the worship to be rendered to God".
Split into simpler sentences: In the aftermath of the plague, many more Days of Obligation were declared by the church. These were days when all people were supposed to go to mass, and "to abstain from those works and affairs which hinder the worship to be rendered to God".