One thing that I may say to them is that no matter what happens Jesus has victory over death (1 Cor 15:55-57). The Lord is in control, and we cannot know when it is our time to be with Him but, that's exactly what life after death is, to be with God! While there are different theories about what happens the moment after we die, we can know with confidence that we will be with Jesus. Nothing can separate us from His love (Romans 8:38-39). And no matter what happens here on Earth, better is one day in the Lords courts than a thousand elsewhere. When it is our time, we will finally be home.