Sexual intimacy between a husband and wife is a reflection of the intimacy God desires with his people. Intimacy with God is shown by the fact that He lives in us (Rom. 8:10; Gal. 2:20; John 17:23). Therefore, the physical intimacy of a husband being inside his wife is a physical picture of the spiritual reality for believers.
Some may wonder where in the bible can one find this connection between sexual intimacy and spiritual intimacy. While the bible does not explicitly state this, we can see it implicitly.
1. Scripture often likens Israel’s worship of idols to adultery and prostitution (Deut 31:16; 1 Chron. 5:25; Ps. 106:39; Is. 1:21; Jer. 3:1, 6; Ez. 16:35, James 4:4). Adultery and prostitution involves sex in both cases. It is the negative image of God’s people being intimate with other gods and forsaking Jehovah.
2. Given this negative image, it follows that there is a positive image. This positive image is faithfulness to God. Faithfulness in marriage means not having sex with anyone except your spouse. In the same way, God does not want us to commit adultery against him, or prostitute ourselves to other gods; we are to be faithful to God by not worshipping anyone or anything else.
3. With the understanding that the bible uses images of marriage and sex to give us a picture of God’s relationship with his people, we can conclude that the physical act of a husband being inside his wife is a picture of the intimacy God has with his people.
4. Some observations:
A. Sex reinforces our commitment and fidelity to our spouse.
B. Sex within marriage between a man and woman glorifies God because it reminds us of the great lengths God went through to have relationship with his people. It reminds us of the gospel.
C. Sex is for procreation, satisfies a physical appetite, and is for enjoyment. However, for the believer, it is so much more than physical, it is spiritual.
D. Sex is a physical, emotional, and spiritual union between a husband and wife.
E. Understanding the “why” of sex helps us joyfully abstain from sex before marriage, and helps to delight in remaining faithful to our spouse in marriage.