Humans may be a disobedient lot by and large, but “be fruitful and multiply” (Gen 1:24) is actually one command we’ve obeyed pretty well. The earth’s population currently numbers seven billion plus souls; and we’re being fruitful and multiplying by the minute.
On the other hand, once you go a little further into the Old Testament, and further still into the New, you find “being fruitful” is not about sex and reproduction anymore. With Israel, and especially with Jesus, being fruitful becomes all about being faithful and filling the earth with the light of Christ. I know it sounds like I’m mixing metaphors here, but I do so on dependable authority. “I made you to go and bear fruit in the world,” Jesus tells his disciples, “fruit that will last.” Fruit that Jesus defines as love. “You are the light of the world,” he says, also alluding to love. “So let your light shine before others, that they may see your good works [your good fruit] and give glory to your Father in heaven.”
Here we tend to limit being fruitful to good works of kindness and generosity we do unto others, especially to people in need in ways that inconvenience us. We gladly give time and money to charitable organizations and churches (hint, hint), and we give the gospel too, sharing our faith and forgiving our debtors as God has forgiven us. To bear good fruit is to be a good Christian.
Yet bearing good fruit is not limited to good deeds, any more than being fruitful is limited to bearing children. Jews and Christians have long understood “be fruitful and multiply and fill the earth” as “the Cultural Mandate.” It has served as a basis for all manner of cultural activity: economic engagement, scientific inquiry, literary exploration, artistic creativity, environmental stewardship and more. Biblically speaking, to do good works is to do good work. To “fill the earth” is to make the most of the world God has made. It is our participation in the creative and redemptive work of God. To fill the earth is to make goods and services rather than just making money. (Goodness and service are very Biblical.) To be fruitful is to enable the earth and its inhabitants to flourish and shine, which gives glory to our Father in heaven.
Even if our tasks have no ‘ultimate significance,’ if done as for the Lord they do have eternal significance. To be sure, sin still pervades work as it has since Adam. But this does not negate the dignity that comes from a job well done. Our work may not be redeeming in and of itself at times, but done for the Lord, it nevertheless provides a foretaste of new creation. When we do our work is for the Lord, we bear fruit that lasts.