There is great controversy over the name of Easter. Several resources, refer to Easter back to the 2nd century. There is a problem with that, namely that Easter is an Anglo – Saxon term that was not used until the late part of the 6th century (that would be Britain). The English language was not solidified until 1645 AD.
According to internet sources, that I can not verify, Easter was celebrated in the 2nd century. The early Church Fathers, do not mention the practice of Easter or the celebration of Resurrection Sunday.
So why is this celebrated? The modern day reason is for the Resurrected Lord. To remember that the tomb is empty and Jesus is alive. Thus the Holy Week, Good Friday, and others.
I am no way down playing these practices. Many perform the observances to help their growth in faith. That is great as long as that is the reason and not another.
Yet remember, the early followers of Jesus did not observe these practices. They were preparing for Jesus’ return and telling others the Good News of the Risen Lord.
There is much work to do to get ready for the return of the Risen Lord Jesus. There is also a vast number of people who need to hear the Good News.