Easter is one of the principal holidays, or feasts, of Christianity. It marks the Resurrection of Jesus three days after his death by crucifixion. For many Christian churches, Easter is the joyful end to the Lenten season of fasting and penitence. The earliest recorded observance of Easter comes from the 2nd century, though it is likely that even the earliest Christians commemorated the Resurrection, which is an integral tenet of the faith.
Easter is celebrated by Christians as a joyous holiday because it represents the fulfillment of the prophecies of the Old Testament and the revelation of God’s salvific plan for all of humankind. In commemorating the Resurrection of Jesus, Easter also celebrates the defeat of death and the hope of salvation. Christian tradition holds that the sins of humanity were paid for by the death of Jesus and that his Resurrection represents the anticipation believers can have in their own resurrection.
In 325 the Council of Nicaea decreed that Easter should be observed on the first Sunday following the first full moon after the spring equinox (March 21). Easter, therefore, can fall on any Sunday between March 22 and April 25. Eastern Orthodox churches use a slightly different calculation based on the Julian calendar. As a result, the Orthodox Easter celebration usually occurs later than that of Roman Catholics and Protestants.