Some Saturday C. S. Lewis" was introduced and explained here. The following quote is from Miracles, with emphasis, as always, original.
On the one hand Death is the triumph of Satan, the punishment of the Fall, and the last enemy. Christ shed tears at the grave of Lazarus and sweated blood in Gethsemane: the Life of Lives that was in Him detested this penal obscenity not less than we do, but more. On the other hand, only he who loses his life will save it. We are baptised into the death of Christ, and it is the remedy for the Fall. Death is, in fact, what some modern people call 'ambivalent'. It is Satan's great weapon and also God's great weapon: it is the holy and unholy; our supreme disgrace and our only hope; the thing Christ came to conquer and the means by which He conquered.