We could also ask the question: “Why does God let bad people die so old?” It doesn’t seem fair, for instance, that a man still alive at 113 years old attributes his longevity to ‘Cigarettes, whisky, and wild, wild women,’ while Job, who was “blameless and upright, a man who fears God and shuns evil” (Job 1:8) was reduced to a pitiful wreck of a man, having lost all his children and his livelihood to a deal Satan made with God. Or that Jesus, who obeyed and trusted God perfectly, was sent to an early death by conniving, power-hungry, religious hypocrites.
Surely good people deserve to live to a ripe old age as proof that God rewards people for living good lives. It’s hardly good advertising on God’s part, then, to let good people suffer from persecution, accidents, all the usual diseases everyone else gets, and premature death, because why would anyone be attracted to Christianity when it clearly doesn’t guarantee immunity from all the things that take humans to an early grave?
So if God isn’t interested in guaranteeing a long life, what is he interested in instead?
One answer Jesus gave in John 3:21 was this: “But whoever lives by the truth comes into the light, so that it may be seen plainly that what he has done has been done through God.” So that’s what life is for. No matter how short or how long a person’s life is, the purpose of it is to make it plain to anyone watching what a human life is like when God is the one shaping and moulding it.
And what makes that so noticeable is the contrast to those in verse 20 who “will not come into the light for fear that his deeds will be exposed.” Some people spend their entire lives hiding from God, and don’t want him involved in their lives at all. But others, like David, willingly opened their lives to God: “Investigate my life, O God,” he wrote in Psalm 139:23-24 (The Message), “find out everything about me. Cross-examine and test me, get a clear picture of what I’m about; see for yourself whether I’ve done anything wrong – then guide me on the road to eternal life.”
David knew there was more going on in his life than trying to extend it for as long as possible. His focus, instead, was on what God could create in him while he was alive, to prepare him expertly for the life David would be living after he died.
And who knows at what age that preparation is complete? Obviously God does, so if he lets a good person die young…