You can thank Emperor Constantine and the Council of Nicea for merging Easter with the pagan celebration of Spring. It was considered pragmatic at the time, since Rome was tearing itself to pieces with Pagans and Christians ripping each other to shreds. Many rituals of Christianity have Pagan origins, including consuming the "flesh and blood" of Christ. It works well with the tradition of the Last Supper, which was the Passover meal Jesus shared with His Apostles. The Sabbath was originally Saturday, as in the Jewish tradition, but got moved to the day that Pagans worshipped the sun, also known as SUNday. Even Jesus, Himself, was merged with the Pagan god Horus; Isis, the ancient goddess and mother of Horus, was also a virgin mother. Also, fun fact, the new year used to begin in Spring. But then King Charle IX of France in 1564 changed it. Those who stuck to the original new year instead of the new one in January were called fools. And that is the story of April Fools Day.