We live in times in which many call good or “no big deal” what God calls sinful. This is especially true in the area of sexuality, where whole sectors of our society not only tolerate but even celebrate sexual practices that the Scriptures call gravely sinful, and which will lead to Hell if not repented of. Acts of fornication (pre-marital sex) and homosexual acts cannot be considered acceptable by any Catholic or by any person who sincerely accepts the Scripture as the Word of God. And even for those who do not share our faith, acts of fornication and homosexual acts can be plainly seen to cause great harm in the manner in which they spread serious disease, harm marriage and family, lead to abortion, and for the children who do survive abortion, subject them to having single mothers, absent fathers, and a lack of the best environment which they are due.

I want to focus today on the terrible and mortal sin of fornication and present the clear biblical teaching against it. Tomorrow I will do the same regarding homosexual acts. Sadly, many Catholics say their pulpits and classrooms are silent about these issues. The hope in this post today is to present a resounding, biblical trumpet call to purity which leaves no ambiguity as to the sinfulness of sex before marriage. Scripture is clear: fornicators will not inherit the Kingdom of God. That is to say, fornication is a mortal sin and those who do not repent of it will go to Hell.

The usual conditions for mortal sin apply (grave matter (which fornication is), sufficient reflection, and full consent of the will). However, we ought not lightly conclude that these conditions are seldom met. I have met with many couples preparing for marriage who are sexually active and I have never found them to be surprised that I rebuke them for this. They know it is wrong. The voice of God stills echoes in their consciences. And as for consent of the will, it can be admitted that some fall occasionally in a weak moment. But consistent fornicating, with no measures taken to prevent it, is not “weakness”; it is sinful neglect of prudence and common sense.

We are in a sinfully confused cultural setting in which many either celebrate or make little effort to avoid what God calls a very serious sin. The Church cannot lack clarity and pulpits and classrooms have often been silent. Such silence has led to parents themselves being silent. And silence has been taken for approval.

But fornication cannot be approved of. It is sinful and may well exclude many unrepentant sinners from Heaven. Our charity for souls must compel our clarity about the grave sinfulness of premarital sex and cohabitation.

Let us turn our attention to the biblical text.

The following quotes from the New Testament are passages that clearly condemn fornication and other unclean or impure actions. Again, fornication is the most common biblical word for premarital sex. The gravity and clarity of such condemnations are helpful in the sense that they help us to take such matters seriously and steer clear of them. However, the condemnations should not be seen in isolation from God’s mercy, as He never fails to forgive those who come to Him with a humble and contrite heart. God hates sin but He loves sinners and is full of mercy and compassion for them. But this mercy must be accessed through repentance.

With this in mind, read the following passages from the New Testament, which condemn fornication and other forms of sexual impurity:

THAT THERE IS A PRESCRIPTION TO GENERAL SEXUAL PURITY – Among you there must not be even a hint of sexual immorality, or of any kind of impurity, or of greed, because these are improper for God’s holy people. Nor should there be obscenity, foolish talk or crude joking, which are out of place, but rather thanksgiving. For of this you can be sure: No fornicator, no impure or greedy person—such a man is an idolater—has any inheritance in the kingdom of Christ and of God. Let no one deceive you with worthless arguments. These are sins that bring God’s wrath down upon the disobedient; therefore, have nothing to do with them (Ephesians 5:3-7).

THAT UNREPENTANT FORNICATORS ARE EXCLUDED FROM THE KINGDOM –

1. The one who sat on the throne said to me, “See I make all things new!” Then he said, “Write these matters down for the words are trustworthy and true!” He went on to say: “These words are already fulfilled! I am the alpha and the omega, the beginning and the end. To anyone who thirsts I will give to drink without cost from the spring of life giving water. He who wins the victory shall inherit these gifts and he shall be my son. As for the cowards and traitors to the faith, the depraved and murderers, the fornicators and sorcerers, the idol-worshipers and deceivers of every sort – their lot is the fiery pool of burning sulphur, the second death!” (Revelation 21:5-8)

2. Happy are they who wash their robes so as to have free access to the tree of life and enter the city through its gates! Outside are the dogs and sorcerers, the fornicators and murderers, the idol-worshipers and all who love falsehood. It is I Jesus who have sent my angel to give you this testimony about the Churches (Rev. 22:14-16).

3. No fornicator, no impure or greedy person—such a man is an idolater—has any inheritance in the kingdom of Christ and of God (Eph 5:5).

4. I warn you, as I have warned you before: those who do such things shall not inherit the kingdom of God! (Gal 5:21)

THAT SINS OF THE FLESH CRUSH THE SPIRIT WITHIN US – My point is that you should live in accord with the Spirit and you will not yield to the cravings of the flesh. The Flesh lusts against the spirit and the spirit against the flesh; the two are directly opposed. This is why you do not do what your will intends. If you are guided by the spirit you are not under the law. The acts of the sinful nature are obvious: sexual immorality, impurity and debauchery, idolatry, sorcery, hostilities, bickering jealousy, outbursts of rage, selfish rivalries, dissensions, factions, envy, drunkenness, orgies and the like. I warn you, as I have warned you before: those who do such things shall not inherit the kingdom of God! (Galatians 5:16-21)

THAT EVEN OUR THOUGHT LIFE IS SUMMONED TO PURITY –

1. You have heard the commandment “You shall not commit adultery.” What I say you to is, Anyone who looks lustfully at a woman has already committed adultery with her in his thoughts. If your right eye is your trouble, gouge it out and throw it away! Better to lose part of your body than to have it all cast into Gehenna. Again, if your right hand is your trouble, cut it off and throw it away! Better to lose part of your body than to have it all cast into Gehenna (Matthew 5:27-30).

2.From the mind stem evil designs – murder, adulterous conduct, fornication, stealing, false witness, blasphemy. These are the things that make a man impure (Matt. 15:19-20).

3. Wicked designs come from the deep recesses of the heart: acts of fornication, theft, murder, adulterous conduct, greed, maliciousness, deceit, sensuality, envy, blasphemy, arrogance, an obtuse spirit. All these evils come from within and render a man impure (Mark 7:21).

THAT SEXUAL IMPURITY IS A FORM OF WORLDLINESS AND IDOLATRY – Put to death whatever in your nature is rooted in earth: fornication, uncleanness, passion, evil desires and that lust which is idolatry. These are sins which provoke God’s wrath (Colossians 3:5-6).

THAT MY BODY IS NOT MY OWN TO DO WITH MERELY AS I PLEASE – Can you not realize that the unholy will not fall heir to the Kingdom of God? Do not deceive yourselves: no fornicators, idolaters, or adulterers, no sodomites, thieves, misers, or drunkards, no slanderers or robbers will inherit the kingdom of God. And such were some of you; but you have been washed, consecrated, justified in the name of our Lord Jesus Christ and in the Spirit of our God. Do you not see that your bodies are members of Christ? Would you have me take Christ’s members and make them members of a prostitute? God forbid! Can you not see that the man who is joined to a prostitute becomes one body with her? Scripture says, “The two shall become one flesh.” But whoever is joined to the Lord becomes one spirit with him. Shun lewd conduct. Every other sin a man commits is outside of his body, but the fornicator sins against his own body. You must know that your body is a temple of the Holy Spirit, who is within – the Spirit you have received from God. You are not your own. You have been purchased at a price. So glorify God in your body (I Cor. 6:9-11, 15-20).

THAT THE CALL TO CHRISTIAN PURITY IS NOT MERELY A HUMAN OPINION; IT IS GOD’S DECLARED TRUTH. FURTHER, SEXUAL SIN IS A FORM OF INJUSTICE – Now my brothers, we beg and exhort you in the Lord Jesus that, even as you learned from us how to conduct yourselves in a way pleasing to God – which you are indeed doing – so you must learn to make still greater progress. You know the instructions we gave you in the Lord Jesus. It is God’s will that you grow in holiness: that you abstain from sexual immorality, each of you guarding his member in sanctity and honor, not in passionate desire as do the Gentiles who know not God; and that each must refrain from overreaching or cheating his brother in the matter at hand; for the Lord is the avenger of all such things, as we once indicated to you by our testimony. God has not called us to sexual immorality but to holiness; hence whoever rejects these instructions rejects, not man, but God who sends the Holy Spirit upon you (I Thess. 4:1-8).

THAT FORNICATION AND OTHER SEXUAL SINS ARE NUMBERED AMONG THE MORE SERIOUS SINS – We know that the Law is good, provided one uses it in the way law is supposed to be used — that is, with the understanding that it is aimed, not at good men but at the lawless and unruly, the irreligious and the sinful, the wicked and the godless, men who kill their fathers or mothers, murderers, fornicators, sexual perverts, kidnappers, liars, perjurers, and those who in other ways flout the sound teaching that pertains to the glorious gospel of God — blessed be he — with which I have been entrusted (I Timothy 1:8-11).

THAT FORNICATION AND ADULTERY DISHONOR MARRIAGE – Let Marriage be honored in every way and the marriage bed be kept undefiled, for God will judge fornicators and adulterers (Heb 13:4).

Therefore do not be deceived; fornication is a serious sin. It is a mortal sin. It is a sin that excludes one who does not repent of it from Heaven. It offends God, harms children and the family, spreads disease, encourages abortion, is an injustice against children and society, dishonors marriage, and merits strong punishment, as God’s Word declares.

Do not despair of God’s mercy, but do repent. Mercy is accessed only by repentance. Little more needs to be said. It is wrong—seriously wrong—to fornicate. Repent at once and without delay.