Easter is a celebration of the resurrection of the Christic force, whether in nature or in an individual.
"...the spring equinox— Easter, the Holy Week [...] is the moment in which [...] the Sun Christ crucifies himself on our planet Earth in order to give life to everything that exists. After his death he resurrects within all creation in order to ripen the grape and every grain. The law of the Logos is sacrifice. This is the cosmic drama that is repeated from moment to moment throughout the infinite space, in all of the worlds, in all of the suns. This is the cosmic drama that is represented in all the temples of Egypt, Greece, India, Mexico, etc. This is the cosmic drama that is represented in all the temples of all of the worlds of the infinite space. The second aspect of this great cosmic drama corresponds with complete exactitude to any sacred individual who by means of the revolution of the consciousness attains the Venustic Initiation and therefore becomes a Solar Hero..." - Samael Aun Weor, Light from Darkness
The word "Easter" comes from Ostara, the name of an ancient Germanic goddess.
Learn more about the real meaning of Easter: The Gnosis of Easter