In 1898 Abraham Kuyper taught a series of lectures at Princeton University. In his lectures, he argued that three fundamental relations encompass all of human life. These three links are "1) our relationship to God, 2) our relation to man, and 3) our relation to the world" (Lectures on Calvinism, p. 11). The understanding of these three issues is the foundation on which each person builds his or her life system or philosophy of life. Included in a life system or a philosophy of life are convictions and perspectives on human sexuality and sexual activity.
The conversation about human sexuality, sexual activity, and the role of sex finds its beginning in understanding the relationship of humanity to God. A Christian understanding of the relationship between God and humanity is founded upon the Bible. A biblical understanding of God's purpose and design for humanity provides the context for rightly understanding all aspects of life, including sexuality and sex.
According to scripture, God created humanity unique from the rest of creation. The Bible says, "God created man in his own image, in the image of God he created him; male and female he created them" (Genesis 1:26-27). Of all creation, only humanity is made in the image of God. Therefore the unique purpose of God for humanity is tied to bearing his image. The image of God isn't related to a particular part of a person—like the emotional, physical, spiritual, or mental aspects of humanity. Instead, the image of God refers to the totality of an individual, not his or her parts.
The essence of an individual cannot be separated from the body, mind, soul, or spirit. The biological makeup of a person is as much who he/she is as his/her thoughts and feelings. But, in today's culture, humanity is divided into so many parts that we have lost the whole, and as a result, many have descended into a moral abyss that ignores God's good design. As Romans 1:23 says, people are "exchanging the glory of the immortal God" for lesser and more debased portraits and designs for humanity, often referring to humanity as another animal or species in creation.
Humanity was not designed to think, feel, or act like the rest of creation. When it comes to sexuality and sexual activity the band Maroon 5 speaks for so many when they sing that we are "just like animals, animals, like animals." God has a higher and more significant role for the purpose of human sexuality and sexual activity. Sex and sexual activity have implications that extend far beyond the momentary pleasure or activity between two people. Sexuality and sex are purposed for God's glory, personal pleasure and satisfaction, and the procreation of the world.
Let's start with the idea that God intends for humanity to procreate. The Bible records God commanding humanity "to be fruitful and multiply" (Genesis 1:28, 9:1,7). The intent of human sexuality is for the purpose of bearing children. As I write this, I am mindful of the many friends and families that I know who desperately want to have children and cannot because of one reason or another. As the father of an adopted child I can speak personally of the joy and blessing that it is to bear fruit through the process of adoption, and yet, I know that it doesn't fully heal the wounds of miscarriages and failed attempts at getting pregnant. However, the experiences of our lives do not discredit the intent and design of God. These difficult realities serve to further illustrate the brokenness of our world and the need for God's promised redemption and restoration through Jesus Christ. Human sexuality has a purpose and design and should be embraced as such. The Christian view of human sexuality is biblically connected to marriage, procreation, and pleasure.
In case you are wondering, having babies requires having sex. Against popular opinion, Christians have sex, and many enjoy it. Seriously, though, the pleasure of sex and the procreation of humanity are both the result of God's good design. God's design for sexuality and sex are exclusively connected to marriage. God created marriage to serve as a sort of living parable to illustrate his relationship with the world. According to Ephesians 5:22-33, the relationship between husband and wife tells the story of God's love for the world through Jesus Christ. The basis for Paul's understanding in Ephesians 5 is his understanding of Genesis 2:24-25. The physical union of husband and wife through sex is a portrait of the unity God intends between himself and humanity. The covenant nature of marriage provides a context that further illustrates the committed relationship between God and his people through Christ.