After He had said this, He told them, “Our friend Lazarus has fallen asleep, but I am going there to wake him up.” — John 11:11

Jesus said of Lazarus,'Our friend Lazarus has fallen asleep'. He means death, but He calls it sleep because that's what it is for believers. We don't want you to be uninformed about those who are asleep — that you may not grieve as those who have no hope. If the dead aren't raised, those who've fallen asleep in Christ have perished. But Christ has been raised, the firstfruits of those who've fallen asleep.