Easter is named after Eostre a saxon (pagan) goddess of new life or fertility or such like.
This is a good example of how early Christians appropriated festivals already celebrated by non-christians in order to draw helpful parallels and explain the gospel (it also explains the eggs and the rabbits - who were not present at Golgotha).
Easter is celebrated each year at approximately the same time as the Jewish Passover (in the western church on the first Sunday following the first full moon after the vernal (or spring) equinox!).
Easter is the Christian Passover.
The Passover lamb's blood was the sign that protected the Israelites in Egypt from the plague of death [Exodus 12:3-13].
Christ has become, for us, our Passover lamb [1 Corinthians 5:7].
He is, as John the Baptist proclaimed, "the Lamb of God who takes away the sin of the world" by His sacrificial death (cf. John 1:29).