"In our culture, where we tend to worship our children and our families, this a particularly challenging idea: that pouring your whole life into your family is about as meaningful in the long run as pouring your whole life into your work. It too is a vanity of vanities that is meant to humble us, and lead us to fear God."
Nothing controversial here, I think. In our lives here 'under the sun,' all things are ultimately pointless. My children's good manners (I wish!), their brains, their accomplishments, all that nature and effort has invested in them... in the end will amount to nothing but a small pile of ash or dust. Death makes a mockery of everything: work, parenting, good health, talent, friendship, love. Even gospel ministry. What's the point in building up a church if in a 10 short decades it will have declined again? If this life is all there is, everything is meaningless.
But there is another world, so everything here - Everything - is invested with meaning and purpose. The work I do is valuable - the children I teach may be spending eternity with Christ! The lowliest work has meaning because it is carried out by one who has eternity in their heart.
In just a few more years we'll see this clearly.