Far too complex for a forum such as this.
Here is a starting point [hope you can access these links!]:
CATHOLIC ENCYCLOPEDIA: Sacrifice of the Mass
Order of Mass: Basic Texts for the Roman Catholic Eucharist
You are touching on a thorny subject here. Christianity is the bedrock of Western civilization, and in its time and place of enormous importance and influence. Even where it is being rejected, its morals and attitudes often survive within the legal systems.
Student or Learner