It's cropped up in several places on the News Feeds this morning: Evidence of interest and curiosity as to what "Easter" is all about.
Not being an in depth scholar of Sumerian mythology, I cannot expound on the meaning of the term itself, only direct you toward what it is SUPPOSED to be about in our day and time. You do not need the fear-mongering & egotism of religion, but only to invest some time reading the Bible & connecting the dots. You might well say, as I did in my youth, "Why NOT go to religion? Surely 'the experts' know more about this!?" but in this particular field, an "expert" is someone you can count on to be right where it doesn't matter and wrong where it does.
You learn about this The Way you learn about anything else:
1. Study (Observe & use Common Sense)
2. Learn the Facts
3. Have the intestinal fortitude to Believe the Fruits of your Research
You may find some pointers that will help here: