A beginning, and its answer
The First Marriage
The first marriage is God's own doing: He sees that it is not good for the man to be alone, and He makes the two one flesh. This first union becomes a picture that reaches to Christ and the church.
“Therefore shall a man leave his father and his mother, and shall cleave unto his wife: and they shall be one flesh.”Genesis 2:24
The first
The first. Amid a creation repeatedly called good, God speaks the first "not good": "It is not good that the man should be alone; I will make him an help meet for him" (Genesis 2:18). God brings the animals to Adam to name, "but for Adam there was not found an help meet for him" (Genesis 2:20). So God causes a deep sleep to fall on the man, takes a rib from his side, and builds it into a woman, then brings her to him. Adam's first recorded words of joy follow: "This is now bone of my bones, and flesh of my flesh: she shall be called Woman, because she was taken out of Man" (Genesis 2:23). Then comes the founding word of marriage itself: "Therefore shall a man leave his father and his mother, and shall cleave unto his wife: and they shall be one flesh" (Genesis 2:24). "And they were both naked, the man and his wife, and were not ashamed" (Genesis 2:25). Before sin, before shame, God joins two into one and blesses them.
What it means
What it means. The first marriage establishes that companionship and covenant union are God's design, not a human invention. God Himself is the maker and the minister of the first wedding; He forms the woman, He brings her to the man, He speaks the word that binds them. Marriage is therefore not merely a contract but a one-flesh union God creates. The language of leaving and cleaving marks it as a new and primary bond, a covenant that reorders all others. That the woman is taken from the man's side, not his head or his feet, has long been read as a picture of equality and nearness, a companion to stand beside him. The first marriage also frames man and woman as complementary and made for one another, and it sets the pattern Jesus Himself appeals to when He is questioned about marriage: "Have ye not read, that he which made them at the beginning made them male and female ... What therefore God hath joined together, let not man put asunder" (Matthew 19:4-6). The permanence and dignity of marriage rest on this first union.
How it points to Christ
How it points to Christ. Paul takes the founding words of Genesis 2:24 and unveils a mystery hidden within them from the start: "For this cause shall a man leave his father and mother, and shall be joined unto his wife, and they two shall be one flesh. This is a great mystery: but I speak concerning Christ and the church" (Ephesians 5:31-32). The first marriage was always pointing beyond itself to the union of Christ the bridegroom with His people. As Eve was formed from Adam's opened side, the church is drawn from the pierced side of the last Adam. Christ "loved the church, and gave himself for it" (Ephesians 5:25), the love a husband is called to imitate. And the story ends at a wedding: "the marriage of the Lamb is come, and his wife hath made herself ready" (Revelation 19:7), where the blessed are those "called unto the marriage supper of the Lamb" (Revelation 19:9). The first union in a garden looks ahead to the everlasting union of the Lamb and His bride.
Questions people ask
Why does God call the man's aloneness not good?
Because human beings are made for relationship. In a creation repeatedly called good, Genesis 2:18 names aloneness as the first thing not good, showing that companionship and covenant union are part of God's design.
What does one flesh mean?
It describes the deep, covenantal, bodily and personal union of husband and wife that God creates in marriage. Jesus cites it in Matthew 19 to teach that what God joins together is not to be broken by man.
How is marriage a picture of Christ?
Ephesians 5 reveals that the one-flesh union of Genesis was always pointing to Christ and the church. The husband's self-giving love images Christ giving Himself for His bride, and history ends at the marriage supper of the Lamb.