1. Refrain from Adultery, the Most Serious Sin

World Scripture

Neither fornicate, for whosoever does that shall meet the price of sin— doubled shall be the chastisement for him on the Resurrection Day.
Qur’an 25.68-69

Let marriage be held in honor among all, and let the marriage bed be undefiled; for God will judge the immoral and the adulterous.
Hebrews 13.4

Whoever has illicit affairs with the wives of his relatives or friends, either by force or by mutual consent, he is to be known as an outcaste.
Sutta Nipata 123 (Buddhism)

But fornication and all impurity or covetousness must not even be named among you, as if fitting among saints. Let there be no filthiness, nor silly talk, nor levity,²³ which are not fitting; but instead let there be thanksgiving. Be sure of this, that no fornicator or impure man… has any inheritance in the kingdom of Christ and of God. Let no one deceive you with empty words, for it is because of these things that the wrath of God comes upon the sons of disobedience.
Ephesians 5.3-6

Approach not adultery: for it is a shameful deed and an evil, opening the road to other evils.
Qur’an 17.32

He who commits adultery is punished both here and hereafter; for his days in this world are cut short, and when dead he falls into hell.
Vishnu Purana 3.11 (Hinduism)

Now Joseph was handsome and good-looking. And after a time his master’s wife cast her eyes upon Joseph, and said, “Lie with me.” But he refused and said to his master’s wife, “Lo, having me my master has no concern about anything in the house, and he has put everything that he has in my hand; he is not greater in this house than I am; nor has he kept back anything from me except yourself, because you are his wife; how then can I do this great wickedness, and sin against God?”
Genesis 39.6-9

Four misfortunes befall a careless man who commits adultery: acquisition of demerit, disturbed sleep, third, blame; and fourth, a state of woe. There is acquisition of demerit as well as evil destiny. Brief is the joy of the frightened man and woman. The king imposes a heavy punishment. Hence no man should frequent another man’s wife.
Dhammapada 309-10 (Buddhism)

Drink water from your own cistern, flowing water from your own well. Should your springs be scattered abroad, streams of water in the streets? Let them be for yourself alone, and not for strangers with you. Let your fountain be blessed, and rejoice in the wife of your youth, a lovely hind, a graceful doe. Let her affection fill you at all times with delight, be infatuated always by her love. Why should you be infatuated, my son, with a loose woman and embrace the bosom of an adventuress? For a man’s ways are before the eyes of the Lord, and he watches all his paths. The iniquities of the wicked ensnare him, and he is caught in the toils of his sin. He dies for lack of discipline, and because of his great folly he is lost.
Proverbs 5.15-23

For this is the will of God, your sanctification: that you abstain from unchastity; that each one of you know how to take a wife for himself in holiness and honor, not in the passion of lust like heathen who do not know God.
1 Thessalonians 4.3-5

The body is not meant for immorality, but for the Lord… Do you not know that your bodies are members of Christ? Shall I therefore take the members of Christ and make them members of a prostitute? Never! Do you not know that he who joins himself a prostitute becomes one body with her? For, as it is written, “The two shall become one flesh.” But he who is united to the Lord becomes one spirit with him. Shun immorality. Every other sin which a man commits is outside the body; but the immoral man sins against his own body. Do you not know that your body is a temple of the Holy Spirit within you, which you have from God? You are not your own; you were bought with a price. So glorify God in your body.
1 Corinthians 6.13-20

Teachings of Sun Myung Moon

Violating and misusing love is the gravest of all sins. Men and women who have been victimized by love often want to commit suicide and throw away their lives. Hence, we should know that committing a sin against love is worse than murder.
(92:79, March 20, 1977)

The critical point in life where Adam and Eve and innumerable heroes and spiritual masters throughout history have failed is the matter of the purity of their sexual love. It is a problem that no one today can solve, not the family, nor the school, the church or the government. I teach the best plan to keep purity: ‘absolute sex.’ What is absolute sex? Once joined in marriage, your relationship to your spouse is eternal. You form an absolute love relationship that will never change under any circumstances. How can that be? It is because as husband and wife you love each other within God’s eternal and absolute love. Absolute sex is not an obligation only for women; it also applies to men. It is Heaven’s principle that all men and women must keep. On the other hand, free sex is a wicked trend that should be completely eradicated from the planet earth. The things associated with free sex—drugs, violence, homosexuality, and HIV/AIDS—only drive humanity down the path to destruction.
(288:283-84, November 30, 1997)

Free sex is like a poisonous snake. Its head is like a man’s sexual organ and its open mouth is like a woman’s sexual organ. One bite from this poisonous snake can spread HIV/AIDS. One bite forever cuts down the ideal world… How can people conquer this snake, employing only their conscience? Coming to their aid, the religions of the world have always taught how to subdue the flesh. They have always commanded, “Do not drink, smoke or engage in free sex!” Only love that is absolute, unique, unchanging and eternal can eradicate free sex. The feeling you get from drugs or alcohol or free sex cannot compare to the absolute joy and stimulation of absolute sex. In absolute sex all the cells in the body and mind activate and connect to the one center. It is supreme ecstasy, far beyond the intoxication of alcohol or drugs. Within its essence lie absolute freedom, absolute happiness, absolute hope, and the absolute fulfillment of all one’s dreams. This is true love… Where is the place where all the cells want to unite? It is [the partner’s] sexual organ. All creatures desire to arrive at their partner’s sexual organ as their final destination. The sexual organs are the connecting point for love, life, lineage and conscience. [Depending on how they are used,] they are the beginning point of heaven or hell.
(279:174-75, August 4, 1996)

Why do we say that one man must love only one woman? What’s wrong with the American lifestyle of one-night stands? Why should we have only one love? Why should there be only one man for one woman? What’s wrong with a man loving several different women and a woman loving several different men? It is wrong because it lacks true love. What is true love? A man’s true love and a woman’s true love is the same. True love does not belong to the man or the woman, but it is the one love that unites both. That is why every man asks his sweetheart, “Do you love me?” and every woman asks her man the same question. Everyone asks their partner, “How much do you love me?” and they answer each other, “I love you more than the universe.”
(118:291, June 20, 1982)

Some married men, when they see a pretty woman, think how nice it would be if she were their wife. Such a person has two minds. We call him a man with the mind of a thief. Satan started from two minds; thus it is right to call such a man with two minds “Satan.” He is no different from Satan.
(Blessing and Ideal Family 1.2.6)

The sexual organ is the most fearful of the senses, because love was the cause of the Human Fall. That is why religions treat adultery as the most serious sin. The free sex that we see in the modern world today is an extension of hell. It is hell on earth and hell in the spirit world. It will entirely perish.
(261:303-04, July 24, 1994)

Love, life, and lineage want to attach themselves to the sexual organs of men and women. They are the place to connect with God. They are the place where the Original Parent of all human beings comes and visits us. The sexual organs are the palace of love, palace of life, palace of lineage, and the palace of conscience. They are the starting point.

Without them, we cannot find love; without them, we cannot find life. Without them, there would be no way for the life in a man and the life in a woman to meet as one. They are where a man and a woman meet and where a lineage comes into being. Your conscience, too, must be in accord with your sexual organ or it cannot manifest correctly. Each of us has love; each of us has life, and each of us has a lineage.

Inquiring where they come from, we learn that they are linked to our parents’ sexual organs. They are linked to the love that is in our parents’ sexual organs. That is how precious these organs are. The core of all the ideal traditions of the universe flows through their gates. The living water of eternal life flows from them. To become eternal living water, there must be love.

So love is the most important. That is how precious these organs are. In nature, precious things, treasures, do not lie in plain view. Instead, they are hidden. Is this not true of gold? It is hidden, distributed in layers of feldspar or other rocks.

However, as the result of the human fall, all this was turned upside down. Each woman now thinks that her sexual organ is her own, but it is not hers. A man can never perfect his love without his wife’s sexual organ. Likewise, a woman cannot maintain her love forever unless she has her husband’s sexual organ to bring love to her. As long as men and women regard their sexual organs as their own, they cannot realize eternal love. Rather, they must exchange their sexual organs.

The owner of a man’s organ is his wife, and the owner of a woman’s organ is her husband… Will a new key fit two different locks? These days some knuckleheaded professors talk about free sex, and say this represents the liberation of love, or the emancipation of sex. They are thieves, and this world has become hell on earth because of such thinking.
(300:320-21, April 15, 1999)