Why is death something to be feared for those who have not experienced identification with Christ?
For those who have not experienced identification with Christ's death, death is indeed to be feared. It does not lead to something better but to something a thousand, a million times worse. Without that identification, death brings an eternal doom rather than resurrection glory, making it horrible to experience.
Les explains that if we have been planted together in the likeness of His death, believing He died our death, then we shall also be with Him in resurrection. That is the blessed hope: the believer does not live and die like a dog or face eternal doom, because death for the saint is glorious and just on to something far better. But for those who have not experienced this identification, death is something indeed to be feared. Les says it is horrible to experience because it is not going to something better; it is going to something a thousand, a million times worse.