Nothing in the world is arbitrary. Everything “seen and unseen,” as the Nicene Creed puts it, has been designed according to the purpose of God. If something is designed, this means it was constructed to fulfill a purpose. Birds are created by God to fly and for that reason, birds have hollow bones and feathers. Their form corresponds to their purpose. Why don’t you use a hammer to mix pancake batter? You could, and it would work to an extent. But a hammer was designed to drive nails and its form—the shape, dimensions, materials, and weight—fits the purpose it was intended to fulfill. What something is supposed to do is reflected by what it is. All creatures fulfill the purpose for which God created them when they live according to God’s design.
Humanity was created by God for two particular purposes. First, as “male and female,” humanity was created to display the “image of God.” Second, as male and female, humanity is to be “fruitful and multiply and fill the earth and subdue it, [having] dominion” over the creatures (Gen. 1:27-28).
Every individual is the image of God regardless of what relationships they may have, but that “image” finds its highest expression in family life because God is Father, Son, and Holy Spirit. The One God has revealed himself to us by using familial language. It should be unsurprising, then, that the story of humanity begins with the consecration of marriage and the story of humanity ends as God’s people are collectively joined to Christ as his bride (Rev. 21-22). The ultimate purpose of male and female—the ultimate “meaning of marriage”— is that it “is a profound mystery” that “refers to Christ and the church” (Eph. 5:32). Every time any man becomes husband to his wife, the nature of God and the gospel itself is displayed. When husband and wife fulfill their vocation to be fruitful and multiply, they are participating in the continuation of creation, reflecting God’s nature. As each generation of new life emerges from the dark, watery wombs of Eve’s daughters, the nature of God who first brought life out of dark waters is revealed (Gen. 1:2).
In creating the world, God provided his creatures with everything needed for their flourishing. In creating humanity, God provided the world with “gardeners” like God who could bring about the world’s potential. In the beginning, there were fruit trees and grain, but the “small plants of the field” (e.g., grapevines) had not yet come up because God had not caused it to rain and there was “no man to work the ground” (Gen. 2:5). Developing the world is a cooperative process. No man can say, “Let there be light,” as God did, but it was a human being who first conceived of a light bulb. God’s intent for humanity is one of exploration, pushing beyond the threshold of human understanding, seeking new and glorious possibilities as society is built up—facing the wildness of God’s good world the same way a gardener examines his yard.
But how are we to cultivate the world successfully from one generation to the next if, as Solomon warns, all the work we do must be “[left] to the man who comes after me, and who knows whether he will be wise or a fool?” (Ecc. 2:18-19). Solomon raises a significant concern: The direction our children go will determine the direction of the world. Family life is a reflection of God’s nature, but it is also designed to be the heart of the church’s discipleship. Speaking of marriage, the prophet Malachi says when God supplies his Spirit so that a couple may have children, God has one intent: “Godly offspring” (Mal. 2:15). Fathers and mothers, because they are like God, bring children into the world after their own image. Children look like their parents, but it is deeper. Children also learn from their parents what is good and true and beautiful, how to interact with others, what it means to be a man or woman, father or mother, and what is valuable in life and worth pursuing. Most importantly, parents train their children, through teaching and living examples, how to worship God. For this reason, every parent must obey the Lord: “You shall teach [God’s commandments] diligently to your children and shall talk of them when you sit in your house, and when you walk by the way, and when you lie down, and when you rise.” (Deut. 6:5-8).
In one hundred years, everyone reading this will be dead and our primary heritage will be our children and grandchildren. The Church is carried on by its converts and its children who have kept the faith. What kind of people will we produce—what direction will our children take the world? Our homes can be like the first garden, where weak Adams fail to protect their families and deceived Eves allow worldly lies to poison their minds. Or our homes can be what they are intended to be—outposts of God’s kingdom, where families worship God together and children are cultivated by attentive parents to become like “tree[s] planted by streams of water, that [yield] fruit in its season” (Psa. 1:3).
Christ came into this world “to destroy the devil’s work” (1 John 3:8). Our children will continue the battle as “a heritage from the Lord [and] arrows in the hand of a warrior” (Ps. 127:3-4). It isn’t a question of whether our children will be part of this war, but whether or not they will assemble with the Lord or with his enemies. They will either become faithful to God and, therefore, dangerous to the devil and his works, or they will function as soldiers in the serpent’s army.
May God grant us the vision of his faithfulness to a thousand generations—countless myriads upon myriads, of every tribe and tongue, sent forth to be fruitful, multiply, and subdue the earth while praying, “Thy Kingdom come, thy will be done on earth as it is in heaven.”
 Unless otherwise stated, all biblical citations come from the ESV.
 Solomon’s concern was warranted. His son, Rehoboam, was a brutal tyrant that saw the kingdom split as the northern tribes rebelled against his brutality (see 1 Kings 12).
 Statements like these from the prophets should be understood in a general sense. Under ordinary circumstances, God intends his people to be fruitful and have children. But in a fallen world, circumstances are frequently outside the norm, as in the tragic case of infertility. Conditions like this are not a barrier to a full and faithful life, nor are they signs of judgment. Many of the greatest heroes of the faith were those who were infertile or struggled to have children. As a result of the fall, there have been disruptions to the creation—disease, physical disability, infertility, etc. But God has a living relationship with each one of us, redeems us in the circumstances of our actual lives, and calls each of us to unique work in his Kingdom, which he planned before the beginning of time (Eph. 2:10).