“For this reason a man will leave his father and mother and be united to his wife, and they will become one flesh” (Genesis 2:24).

Sex is the process by which many living things reproduce, from plants, trees and animals, to birds, fish and people.

Sex is also one of the most incredible processes ever conceived in the mind of God.  I’ve been at the birth of each of my children, and the way a child is born is astounding.  But I’ve also been at the conception of each of my children, that moment in time when they were created, and I can say that the way a child is conceived in the first place is equally astounding, if not more so!

I’d like to describe that process to you here, as God has revealed it to us through the design of nature itself.  Although I’ve taken great care to describe this process in a simple way, don’t mistake my simple description for a simple process. The human reproductive system is one of the most intricate and complex systems ever created.

Sex 101

Babies are very fragile and need a safe place to grow, so God created just such a place inside each woman called a womb.  The womb is made of a soft, expandable tissue that gently cuddles a baby.

But a baby doesn’t start as a full-grown baby; it starts as a tiny egg, smaller than the dot at the end of this sentence.  When a woman reaches puberty, the age when she’s old enough to start having children, God designed her body to begin to release eggs into her womb.  About once every month, an egg is released from a small holding area, called an ovary, just above the womb.  When the ovary releases the egg, the egg glides down a thin tube towards the womb.  There are two of these ovaries and two of these tubes that lead into the womb.  Only one of the ovaries will usually release an egg each month.

The egg gradually makes its way through the tube, waiting to be fertilized, something I’ll discuss below.  If the egg isn’t fertilized within a few days, it simply travels on through the womb and down a larger tube that comes out of a woman’s body called the vagina.  The vagina is the central opening of the three openings between a woman’s legs.  The urethra, where the urine, or liquid waste comes out, is in front of the vagina, and the rectum, where the bowel movements, or solid waste comes out, is behind it.

The egg that comes out of the vagina is too small to be seen, but some of the blood that lines the inside walls of the womb does come out with the egg as a way of cleansing the womb before the process starts all over again.  Because this flow of blood containing the egg usually happens about once a month, or periodically, people call this monthly flow a period.  

The next month, the process starts over and another egg is released from one of the ovaries.  This egg then travels down the tube, called the fallopian tube, towards the womb, also called the uterus, to be possibly fertilized.  If the egg isn’t fertilized, it travels on through the womb and down the vagina, then comes out with the blood from the womb in the next period.

The release of eggs within a woman is important, but without fertilization, a baby can’t be created.  Fertilization is the spark that creates a new life.  Fertilization occurs when something called a sperm comes into contact with an egg.  Sperm are also very tiny; they’re even smaller than the egg.

But a woman’s body doesn’t produce sperm.  Sperm are only produced inside a man’s body.  Just as a woman’s body contains two ovaries where eggs are stored, a man’s body contains two testicles where sperm are produced.  These two testicles are held in a sack of skin, called the scrotum, found between a man’s legs.  The sperm must be kept a little cooler than the rest of the body, so God created this sack to hang just outside the man’s body to keep the temperature just right.

When a man gets old enough to start having children, his testicles begin to produce sperm.  Since a sperm and an egg must come into contact with each other in order to create a child, God designed a way to get the sperm and egg together without ever having to travel outside a human body.  And the way God brings the sperm and egg together is through this incredible experience called sex.

Our bodies are wired with special nerves near the surface of our skin that can make us feel great when someone gives us a hug or a kiss.  But God has saved a romantic kind of hugging and kissing that we can enjoy with our husbands or wives that can feel even more amazing.

During these special times of hugging and kissing, a man’s penis is stimulated by all the touching so that it becomes straight and firm, even though it’s still soft to the touch.  The penis becomes this way as blood rushes into it and flows into a unique type of body tissue found in the penis.

As the man and woman snuggle closer to each other, his penis begins to release a smooth, clear, lotion-like fluid called semen.  In the same way, the woman’s body releases a similarly smooth and clear fluid that lubricates her vagina, the tube that leads into her womb.  All of this naturally produced lotion makes the rubbing and touching even more smooth and wonderful.

God has designed the woman’s vagina to be soft and expandable so that her husband’s penis can fit softly and snugly inside it.  As a man and woman continue to love each other in this way, with his penis gently rubbing inside her vagina, the rubbing movements eventually trigger millions of these minuscule sperm to be released from the testicles and they combine with the semen.  The combined sperm and semen then travel up through the penis and into the woman’s vagina and then on into the woman’s womb.

The release of sperm from the man’s body is called  an ejaculation.  At this climactic moment, both the man and woman will often feel an intensely pleasurable sensation called an orgasm.  In this way, God is able to get the sperm from the man’s body into the womb of the woman’s body without ever having to travel outside the human body!

If one of the woman’s ovaries has already released an egg into the tube leading to the womb, the first sperm to reach the egg and come into contact with it sparks the process of fertilization.  When that happens, a moment called conception, a new life is created and begins to grow in the womb.

After the sperm has been released from the man into the woman, the man’s penis begins to relax, and the husband and wife can continue to hold each other, hugging and kissing as long as they want.

The biological term for this process is sexual intercourse, which is usually just shortened to the word sex.  Because this process feels so great and makes a husband and wife feel so loved by each other, the experience is sometimes called making love.

God calls it becoming one flesh:

“For this reason a man will leave his father and mother and be united to his wife, and they will become one flesh”  (Genesis 2:24).

I call it a miracle!  I’ve never experienced anything like it in all my life.

When I first learned about sex, I thought that it was one of the most unusual things I had ever heard.  But since then, I’ve learned that it’s not unusual at all to God.  This is the process He’s been using for thousands of years to create new life.

If you ever have questions about sex, or about anything for that matter, ask God to give you His wisdom.  He’ll be glad to pour it out on you in abundance:

“If any of you lacks wisdom, he should ask God, who gives generously to all without finding fault, and it will be given to him” (James 1:5).

Review Questions

1. What two things does God bring together through sex to create a child—one from a woman’s body and one from a man’s?

2. What happens to a woman’s egg if it has not been fertilized within a certain period of time?

3. What does God say that a man and his wife become when they are united together?  (Genesis 2:24)

4. What does God promise to give generously to those who ask Him for it? (James 1:5)