On Sunday, we must first begin the day by going to Sunday Mass. After worshiping God, it is important to spend time doing restful activities, because it is God's day, meaning we must sanctify the day by making Sunday a day different from all other days. Simply put, Sunday is a day of rest from work.  If some work is necessary for Sunday, do what needs to be done, and leave what is not necessary for another day. To understand the concept of resting from work on Sunday, and going to Sunday Mass (The Third Commandment) even more, check out the following: