In our culture, sexual relationships are where Scripture seems most contrary to the majority opinion, and the majority opinion affects us more than we realize.
Cohabitation is an example. In my own lifetime, it has gone from shameful, to frowned upon, to “better than the alternatives,” to accepted, to a necessary phase of every relationship that is to be celebrated. Marriage, after all, did not seem to help many of our parents stay together.
As a way to revisit the subject, consider the apostle Paul’s thick and fresh pastoral arguments in chapter six of his first letter to the Corinthians. His purpose is important. He wants to show the connection between Scripture’s words about sexuality and “Christ and him crucified” (1 Cor 2:2). I have included the passage below, but since it presents some lesser-used reasoning, I will also paraphrase it, which I have found to be a useful practice with difficult passages. Paul, I hope, would approve.
Here is the original.
“All things are lawful for me,” but not all things are helpful. “All things are lawful for me,” but I will not be dominated by anything. “Food is meant for the stomach and the stomach for food”—and God will destroy both one and the other. The body is not meant for sexual immorality, but for the Lord, and the Lord for the body. And God raised the Lord and will also raise us up by his power. Do you not know that your bodies are members of Christ? Shall I then take the members of Christ and make them members of a prostitute? Never! Or do you not know that he who is joined to a prostitute becomes one body with her? For, as it is written, “The two will become one flesh.” But he who is joined to the Lord becomes one spirit with him.
Flee from sexual immorality. Every other sin a person commits is outside the body, but the sexually immoral person sins against his own body. Or do you not know that your body is a temple of the Holy Spirit within you, whom you have from God? You are not your own, for you were bought with a price. So glorify God in your body. (1 Cor 6:12–20)
Here is a paraphrase.
Notice how we can find a belief, somewhere in our souls, that we are independent agents, free to make our own decisions. This belief can be aroused when we hear that we “are not under law but under grace” (Rom 6:14). But be careful. Even people who don’t follow Jesus would say that freedom has its limits. Some choices are good for us and some are not.
Let’s go further in. We also have other beliefs that need more careful attention. For example, we decide that some things are not that big of a deal. You don’t have to come to a complete stop at every stop sign. And sex? It doesn’t seem to hurt anyone. It is a natural, bodily thing—and even though it is an unusually strong desire, it does not have spiritual permanence. Sex will not exist in heaven, so it can’t matter that much. Let’s get on with more important spiritual matters. To quote a Christian professor’s passing comment, “Why would God care so much about what we do with our genitals?”
But here is the truth. We “belong—body and soul—both in life and in death, to our faithful Savior Jesus Christ” (Heidelberg Catechism). Jesus has not claimed only your soul. He claims all of you. Jesus came to us in a physical body, he was raised body and soul, and we will see him in the flesh. Our bodies matter. What we do with our genitals matters.
And now to some deep mysteries. When you come to Jesus by faith, you are joined to him, body and soul. That is what the Spirit does. It’s a mystery to be sure, but true. You belong to Christ; you are part of Christ; you are an extension of Christ. His body is given for you; your body is joined to him.
It turns out that there are different ways to be joined or united with someone.
We can be joined to a person through a sexual act.
We can be joined to a spouse by a covenant, which can be expressed in a sexual relationship.
We can be joined to Christ by a covenant, which is expressed as faith.
With this in mind, how could you join your body to someone who Christ has not given you? Sex is joining yourself to another, and when it is illegitimate, it profanes the name of Christ. Think of how adultery is dishonoring and catastrophic to marriages. Therefore, if we enter into a covenant with Christ, and then establish a new one in an illegitimate sexual relationship, we dishonor him, and the impact can be catastrophic.
If you are to live out your new identity in Christ, which, ultimately, is the most satisfying thing you could possibly do, run from sexual temptation—Joseph-like. Don’t think; run. If you think, you will surely rationalize a decision to rain havoc on your entire being. Run. When you are sane, you might be able to see that sexual sin is a unique sin that brings its own quiet version of death on our bodies and souls.
One other thought. Do you know that your union with Jesus is such that the Spirit of Jesus is truly within you? That makes you a holy tabernacle. Only those things authorized by God—aka sanctified—may be brought in. Anything else desecrates your very body and dishonors Christ.
To summarize all this: You are not your own; you were bought at a price. You are not a free independent agent who is above God’s law, and God cares profoundly about what you do with your body. As a way to plant this in your soul, start your day with this summary, remember it, speak about it, and list a few ways that it could change your day: “This is the good life. It can only be found in Jesus. It is not found in splitting my allegiances between Jesus and an unconsecrated relationship (to use tabernacle language). May the Spirit give me seeing eyes and an open heart so these realities possess me fully.”