The Seriousness of Sexual Immorality – [Part 2 of 2]



Ephesians 5:3

3 But among you there must not be either sexual immorality, impurity of any kind, or greed, as these are not fitting for the saints. (NET)


This continues our discussion from Part One about the sin of sexual immorality” among God’s people. Here I want to answer the question of why committing this sin is such a serious matter for Christians.

To begin with, our position in Christ is one of absolute purity. We are new creations in Christ (2 Cor 5:17). We have been given a new nature, in the likeness of God’s own nature. Thus we are to always be living according to who we are as children of God, for like begets like. We’re always to be growing into our holy position in Christ.

To live contrary to who we are is to miss the whole point and purpose of salvation. Salvation is not simply about going to Heaven. It’s about being brought into a right relationship with God. It’s about being set free from the penalty and power of sin. It’s about a whole new life, a whole new direction. Those who profess Christ as Lord and Savior, but continue year after year to live according to the ways of this world, with little or no concern about personal purity or faithfulness to God, are not genuine believers. They have not been born-again. Those who have experienced true salvation, will produce the fruit of salvation — the fruit of true faith in Christ.

Professing Christians who have a casual view of sex outside of marriage, and engage according to that view, demonstrate a serious lack of sensitivity to the convicting work of the Holy Spirit. If a Christian has gotten to that point, that is reason for great concern about where they’re at spiritually.

The purpose of this discussion is to awaken people to the gravity of sexual sin as followers of Christ. Perhaps this will apply personally, or you may know someone who professes Christ, but practices sex outside of marriage or engaged in adultery. Whatever the case may be, Christians need to be taught the truth about this sin. I fear that few are being taught as they should be today.


Why is Sexual Sin Such a Serious Matter?


To answer this question, we must go to the book of 1 Corinthians:


(1 Corinthians 6:11-20) — 11 Some of you once lived this way. But you were washed, you were sanctified, you were justified in the name of the Lord Jesus Christand by the Spirit of our God. 12 “All things are lawful for me” – but not everything is beneficial. “All things are lawful for me” – but I will not be controlled by anything. 13 “Food is for the stomach and the stomach is for food, but God will do away with both.” The body is not for sexual immorality, but for the Lord, and the Lord for the body. 14 Now God indeed raised the Lord and he will raise us by his power. 15 Do you not know that your bodies are members of Christ? Should I take the members of Christ and make them members of a prostitute? Never! 16 Or do you not know that anyone who is united with a prostitute is one body with her? For it is said, The two will become one flesh.” 17 But the one united with the Lord is one spirit with him. 18 Flee sexual immorality! “Every sin a person commits is outside of the body” – but the immoral person sins against his own body. 19 Or do you not know that your body is the temple of the Holy Spirit who is in you, whom you have from God, and you are not your own? 20 For you were bought at a price. Therefore glorify God with your body. (NET)


According to verse 12, we’re not to be “controlled by anything.” As those who are to be under the control of the Spirit, we’re not to be enslaved by anything. Sex enslaves.

In verse 13, Paul says that “the body is not for sexual immorality, but for the Lord.” Our bodies have been set apart by God for Himself, for His purposes, and that does not include sex outside of marriage or adultery or any other kind of sexual sin. God has set apart our bodies for purity, to be used in an honorable manner for His glory. When we engage in sexual sin, we dishonor the name of Christ. We’re doing something with our bodies that they were never intended for, except in marriage. We’re desecrating what God designed for holiness.

Paul also says that “the Lord is for the body.” This is an unusual statement. What does that mean? Albert Barnes is very helpful here:


Quote: The Lord is in an important sense for the body, that is, he acts, and plans, and provides for it. He sustains and keeps it; and he is making provision for its immortal purity and happiness in heaven. It is not right, therefore, to take the body, which is nourished by the kind and constant agency of a holy God, and to devote it to purposes of pollution.” That there is a reference in this phrase to the resurrection, is apparent from the following verse. And as God will exert his mighty power in raising up the body, and will make it glorious, it ought not to be prostituted to purposes of licentiousness.



Since God is going to resurrect our bodies some day – in total sinless perfection – we should live our lives with that in view. In other words, since the resurrection of our bodies into the presence of God is our great hope, it’s completely contrary to use our bodies in a manner that does not reflect that hope.

In verses 15-17, Paul talks about our spiritual unity with Christ. Through faith in Him, we become one spirit with Him. We have a spiritual oneness with God that is holy. Thus we are not to pollute that holy union, not by way of a “prostitute” or by way of anyone else, as Paul makes clear in verse 18 where he mentions “sexual immorality.” By way of reminder, this is the Greek word “porneia,” which is the general term for all forms of sex outside of a holy, marital relationship.

Again in verse 18, Paul tells us to “flee sexual immorality.” The Greek word for “flee” is pheugo, which means to seek a place of safety out of danger by way of flight. This is a very descriptive word. Paul is not simply telling us to avoid sexual sin or to walk away from it. He’s telling us to run for our lives! So serious is this sin, that we are to run away from it as though we were running away from an unmerciful killer. For sexual sin is indeed a killer.

This sin destroys in a way that no other sin does. It affects us spiritually in a way that no other sin does. And that is what Paul talks about in verses 18 and 19. Every other sin that we commit is outside the body. I believe what Paul is saying here is that there are no other sins where our bodies are so directly and completely and intimately involved as sexual immorality. Paul says that such engagement is sin against our bodies, because in doing so we defile the “temple of the Holy Spirit,” which is our bodies.

Sexual sin pollutes the holy temple of God. Since we have a spiritual union with God, and since we come into a certain union with the one we’re having sex with, we defile the pure union we have with God when committed outside of His holy design for it. To join that which is holy with that which is unholy is an abomination to God. Thus sexual sin affects us spiritually in a way that no other sin does. There is something very profane about sexual sin, something about it that has a powerfully adverse affect on our spiritual relationship with God.

Very clearly then, sex is not merely a physical act. There’s also a deep, spiritual aspect to it, especially for Christians within marriage. John MacArthur gives a wonderful description of the husband and wife relationship:


Quote: In marriage a man and woman are so closely joined that they become ‘one flesh,’ which involves spiritual as well as physical oneness. In marriage God brings a husband and wife together in a unique physical and spiritual bond that reaches to the very depths of their souls. As God designed it, marriage is to be the welding of two people together into one unit, the blending of two minds, two wills, two sets of emotions, two spirits. It is a bond the Lord intends to be indissoluble as long as both partners are alive. The Lord created sex and procreation to be the fullest expression of that oneness, and the intimacies of marriage are not to be shared with any other human being.


(John MacArthur Matthew 1-7, Moody, 1985, p. 311).


When we place our faith in Christ, we enter into a spiritual union with Him. It’s a type of relationship that can be compared to marriage (Eph 5:22-33). The Bible actually refers to the people of God collectively as “His Bride” (Rev 19:7-9). When we receive Christ, we enter into that union, into that marriage. We become completely His, and He becomes ours.

When Christians marry, they too enter into a union with each other. This is a holy union that God has ordained and blessed, and is in perfect harmony with the holy union that we as believers have with Him. Sex between a Christian husband and wife is a wonderful spiritual experience, for it’s a holy union in the sight of God, enjoyed in holy union with God.

The unsaved don’t have a spiritual union with God, so when they commit sexual sin, they’re not affected the same way Christians are. Nor is it exactly the same sin. In a certain way, we’re talking about two different types of sin here. Sexual sin committed by non-Christians is purely physical. Sexual sin committed by Christians affects the whole of our spiritual being. When Christians commit adultery or engage in sex outside of marriage, there’s an unfaithfulness to God involved that is on a very deep and unique level, that is not and cannot be experienced by non-Christians.

As vivid as I attempted to be in describing the seriousness of sexual sin among Christians, I feel that it’s still inadequate to the actual reality of it. Only God is able to see the full reality of its sinfulness and how it affects our relationship with Him. However, what has been revealed to us should cause any true born-again believer in Christ to shake in their boots.


Final Word of Caution

Those who profess to be followers of Christ, but are involved in unrepentant sexual sin year after year, without any real sense of concern or conviction, their salvation comes into serious question. In Ephesians 5:5-6, Galatians 5:19-21, 1 Corinthians 6:9-10, Paul lists numerous examples of sins that prevent people from “inheriting the Kingdom of God.” Sexual immorality is named in all three of these lists. What Paul is teaching in these passages is that those who practice a lifestyle of sin (lives that are characterized by sin), demonstrate a lack of genuine faith in Christ—an absence of true salvation. If this truth, this warning, doesn’t turn a professing believer away from their sexual immorality, then it reveals a hardness of heart that is characterized only by the unsaved.


This is a wake-up call.