On the third day after his crucifixion, Mary Magdalene came to the tomb in the early morning and found the stone rolled away and the body gone. The risen Christ appeared to her in the garden; she at first mistook him for the gardener until he spoke her name.
Over the next forty days he appeared repeatedly: to Peter, to the disciples behind locked doors, to two travelers on the road to Emmaus who recognised him in the breaking of bread, to doubting Thomas who placed his hand in the side-wound, to seven disciples by the Sea of Galilee, and — as St. Paul writes — 'to more than five hundred brothers and sisters at one time, most of whom are still alive, though some have died' (1 Cor 15:6).
On the fortieth day he ascended to the Father, leaving the apostles with the commission to preach the Gospel to all nations. The Resurrection is the foundation of every other miracle the Church proclaims: 'if Christ has not been raised, then our proclamation has been in vain' (1 Cor 15:14).