The Resurrection is the Defeat of Death

“Of old, before the Savior made his divine sojourn on earth, all lamented the dead as though destruction awaited them, but now that in these latter days the Savior has raised his body, death is no longer fearful–rather, those who are in Christ trample it as a thing of no account and choose to die rather than deny their faith in Christ.

For they know that when they die they are not undone but live and become incorruptible through the resurrection. But as for the devil, he who of old exulted basely in death, his labor is now undone, and he is left as the only one who is truly dead. […]

When after night the sun rises, and the whole of the neighboring land is illumined by it, not the slightest doubt remains that the sun who sheds his light everywhere is also the one who drove away the darkness and illumined everything.

In just the same way, death was trampled and brought into contempt from the time when the Savior made his appearance in the body for our salvation, and the end of the Cross became manifest; this was enough to make plain that he himself was the Savior, the one who had trampled death, and was displaying the trophies of victory over it every day in his disciples.”

–Athanasius, On the Incarnation, 27.2-3; 29.3 in Mark J. Edwards, ed., We Believe in the Crucified and Risen Lord(IVP, 2009), 147-150.