Well, if it's anything like the promise the bible says Jesus made about his return, then I don't have anything to worry about.
“For the Son of Man is going to come in the glory of His Father with His angels, and will then repay every man according to his deeds. Truly I say to you, there are some of those who are standing here who will not taste death until they see the Son of Man coming in His kingdom.“ (Matthew 16: 27, 28)
Unless some of those who were standing there found the secret of long life, they will be long dead.
I know, Iknow, you're going to tell me what it said is not what it actually means.
As Alice said in Wonderland, it gets "curiouser and curiouser".