This morning, we are picking up in part two of our series, The Naked Truth, where we are taking an honest look at marriage. Today’s message is entitled “The other side of love”, and in this message, we are going to discuss the topic of sexual purity.

Once again, if you missed it earlier, parents, we have provided the opportunity for those in middle school to step back into kids’ service this week if you feel the topic is not something you would like them to hear.

Topics like this have seemed to be considered taboo subjects, but I think they are important to talk about because silence gives room to the enemy. If we are silent spiritually, it gives room for Satan to twist, distort, and manipulate our understanding of God’s design, opening the door to sexual perversion.

As we jump in, let me give you a quick recap of last week to bring you up to speed if you weren’t here. In answering a question about cohabitation, we contrasted contract vs. covenant. That what we join ourselves to we become one with, and what we become one with we carry with us into the future. One key aspect that we briefly discussed was the issue of maintaining sexual purity, and that there is no such thing as casual sex. God designed sex as a sealing mechanism that joins two lives like spiritual adhesive.

Genesis 2:24 “Therefore a man shall leave his father and mother and be joined to his wife, and they shall become one flesh.” The term “one flesh” implies a new, single entity.

Last week’s message, along with another question submitted for the Let’s Talk about it series, has set the stage to look at the broader topic of sexual purity. The question was related to masturbation before or after marriage and whether or not it was a sin.

As we begin, I want to create a proper framework for the mind concerning this topic. Biblical purity is about more than rule following; it is about the environment of your soul.

To understand Biblical instructions concerning intimacy we must orient our hearts to the truth.

The command to flee youthful lust and instead pursue righteousness, faith, love, and peace is about the purity of your heart and your service to the Master. Paul reminds us, that we are not our own, we have been purchased by Christ, and our response is to glorify Him in our body and spirit.

The central understanding we must gain is that every dimension of our life belongs to Him, including our sexuality. Internally, we cannot have a disposition that is segmented. My Christian life, work life, friend circle, home life, sex life, etc.

We are one in Him, purchased by the blood of Jesus, and the totality of who we are is under His lordship. The kingdom of God is about submission to His ways, not individualism.

Now with that truth in mind, remember that we are created by God for intimacy. What God designs is good, but it is to be enjoyed within the context of His design. The marriage covenant is designed to help us flourish and enjoy our sexuality, while simultaneously protecting the environment of our souls.

God does not want to keep us from pleasure; He wants to keep us from perversion.

To protect the environment of our soul the word instructs us to flee sexual immorality. Why? First, to honor God. Secondly, to keep from partnering with our own destruction.

The issue of sexual immorality isn’t just about sin and rules; it is about protecting biology that God created. Violation of His design causes your own biology to work against you.

Here is how sexual activity "rewires" the brain through three primary mechanisms:

1. The "Chemical Glue": Oxytocin and Vasopressin
During sexual intimacy and even deep physical touch, the brain’s hypothalamus produces two powerful hormones that act as a form of "biological velcro."
• Oxytocin (The "Love Hormone"): Primarily released during skin-to-skin contact and orgasm. 2 It lowers stress, increases trust, and builds a sense of "emotional safety." 3 Its job is to make you feel bonded and attached to the person you are with.
• Vasopressin (The "Monogamy Hormone"): This hormone is particularly active in men. It is linked to "mate-guarding" and the desire to stay and protect a partner.

The Rewiring: These chemicals create a neural "imprint" of your partner. In a covenant marriage, this rewiring is a gift that makes staying faithful easier over time. Outside of that context, it creates a "bond" with someone you may not actually be committed to, leading to the "soul tie" confusion discussed earlier.

2. The "Dopamine Superhighway"
Sexual activity triggers the brain’s reward system, flooding it with Dopamine. This is the same circuit activated by addictive drugs. It creates an intense rush and assigns massive importance to the activity.

The brain through neuroplasticity is rewired to desire that specific reward the more often the behavior is engaged with. So with sexual immorality the more often you engage in sexual behavior or with a specific person, the brain builds a “superhighway” through strengthened synaptic connections.

The Rewiring: Your brain literally learns to "crave" the person or the act. If the activity is focused on novelty (multiple partners, pornography, masturbation, etc.), the brain can be rewired to prioritize variety over intimacy, making it harder to settle into the "slow-burn" peace of a long-term marriage.

3. The "Prefrontal Shutdown"
One of the most significant ways sex affects the brain is by temporarily "deactivating" the Prefrontal Cortex—the part of the brain responsible for: Critical thinking and logic, Impulse control, and Predicting consequences.

The Rewiring: During arousal and intimacy, your "logical brain" takes a backseat to your "emotional brain." This is why people often say or do things in the "heat of the moment" that they wouldn't normally do. If this happens repeatedly outside of a safe covenant, you can "train" your brain to bypass your values, making you feel like a passenger to your own impulses.

The Good News of Neuroplasticity is your brain can be rewired. Just as you have created pathways through unhealthy patterns, you can also break those bonds and rewire your brain.

Over time, the brain can "atrophy" (weaken) old, unhealthy connections and build new "highways" of faithfulness. This mirrors the biblical concept of being "transformed by the renewing of your mind" (Romans 12:2).

The key aspect of the command to flee sexual immorality is protection. We don’t want to create an environment where we train our brains to bypass our values. Leaving us with imprints of people and habits that we become slaves to.

The covenant of marriage allows your biology to work for you and not against you. The biology and desires themselves are not evil. They were given to us by God, but they must be stewarded like everything else. It is all about timing.

Paul, speaking to the Thessalonian Church, instructs in 1 Thessalonians 4:3-5.

Abstinence is about protecting the inner man and becoming a vessel of honor. We have seen today that outward physical actions affect the condition of the inner man both spiritually and biologically.

Lustful passions left unchecked create an environment for defilement and perversion. In simplicity, sexual activity outside of covenant we are to avoid. This also includes things like masturbation, pornography, fantasy novels, dirty movies, etc.

The reason: Jesus told us evil thoughts originate from within. Matthew 5:27–28 “You have heard that it was said to those of old, ‘You shall not commit adultery.’ But I say to you that whoever looks at a woman to lust for her has already committed adultery with her in his heart.”

If we want to be successful, we must protect the inner man. Proverbs 4:23 “Keep your heart with all diligence, For out of it spring the issues of life.”

A final thought concerning the marriage bed and keeping it holy. Hebrews 13:4, “Marriage is honorable among all, and the bed undefiled; but fornicators and adulterers God will judge.”

What’s prohibited?
Adultery. Exodus 20:14. Polygamy: Inviting others into the marriage bed. Matthew 19:4-6. It is for one man and one woman. Pornography: Is virtual adultery. Matthew 5:27-28.

What’s permitted?
First question: Is it prohibited in Scripture?

Second question, is it beneficial? Does it cause harm in any way?

Third question: Is there mutual consent? If the other spouse is forced into an act or is uncomfortable participating, then it is not okay, even if the bible is not against it, and there doesn’t seem to be any apparent harm. We are called to honor God and respect each other.

Fourth question: Does the act violate your conscience? Does the act violate the conscience of your spouse? Is there a sense of conviction attached to a specific act?
As I bring this message to a close, remember that Biblical purity is about more than rule following; it is about the environment of your soul. Our aim is to honor God in every area of our lives, and it is in our best interest to align ourselves with His design.

In all that you do, position yourself for close proximity with Christ. Let there be no area of your life that He doesn’t have access and authority over.