Offenses Against the Dignity of Marriage

Folks, this is what the Catechism of the Catholic Church teaches about the Sixth Commandment ("Thou Shall Not Commit Adultery") and the offenses against the dignity of marriage:

Adultery

2380 Adultery refers to marital infidelity. When two partners, of whom at least one is married to another party, have sexual relations - even transient ones - they commit adultery. Christ condemns even adultery of mere desire.170 The sixth commandment and the New Testament forbid adultery absolutely.171 The prophets denounce the gravity of adultery; they see it as an image of the sin of idolatry.172

2381 Adultery is an injustice. He who commits adultery fails in his commitment. He does injury to the sign of the covenant which the marriage bond is, transgresses the rights of the other spouse, and undermines the institution of marriage by breaking the contract on which it is based. He compromises the good of human generation and the welfare of children who need their parents' stable union.

Divorce

2382 The Lord Jesus insisted on the original intention of the Creator who willed that marriage be indissoluble.173 He abrogates the accommodations that had slipped into the old Law.174

Between the baptized, "a ratified and consummated marriage cannot be dissolved by any human power or for any reason other than death."175

2383 The separation of spouses while maintaining the marriage bond can be legitimate in certain cases provided for by canon law.176

If civil divorce remains the only possible way of ensuring certain legal rights, the care of the children, or the protection of inheritance, it can be tolerated and does not constitute a moral offense.

2384 Divorce is a grave offense against the natural law. It claims to break the contract, to which the spouses freely consented, to live with each other till death. Divorce does injury to the covenant of salvation, of which sacramental marriage is the sign. Contracting a new union, even if it is recognized by civil law, adds to the gravity of the rupture: the remarried spouse is then in a situation of public and permanent adultery:

If a husband, separated from his wife, approaches another woman, he is an adulterer because he makes that woman commit adultery, and the woman who lives with him is an adulteress, because she has drawn another's husband to herself.177

2385 Divorce is immoral also because it introduces disorder into the family and into society. This disorder brings grave harm to the deserted spouse, to children traumatized by the separation of their parents and often torn between them, and because of its contagious effect which makes it truly a plague on society.

2386 It can happen that one of the spouses is the innocent victim of a divorce decreed by civil law; this spouse therefore has not contravened the moral law. There is a considerable difference between a spouse who has sincerely tried to be faithful to the sacrament of marriage and is unjustly abandoned, and one who through his own grave fault destroys a canonically valid marriage.178

Reflection. There's no room to maneuver here. The prohibition against adultery reaches all the way back to the Decalogue and probably before. Jesus himself extended explicitly the consequences of this sin. The prohibition is absolute, as the Catechism states, and there is no leeway for excuses, mitigations, exceptions. You do this freely and with full knowledge, and you're committing a mortal sin. You die without repenting of this sin and you will not enter the presence of God. The author of the Book of Proverbs describes with great precision the mindset and the consequences of adultery:

Proverbs 5

Warning Against Adultery

1 My son, pay attention to my wisdom,
listen well to my words of insight,
2 that you may maintain discretion
and your lips may preserve knowledge.

3 For the lips of an adulteress drip honey,
and her speech is smoother than oil;

4 but in the end she is bitter as gall,
sharp as a double-edged sword.

5 Her feet go down to death;
her steps lead straight to the grave. [a]

6 She gives no thought to the way of life;
her paths are crooked, but she knows it not.

7 Now then, my sons, listen to me;
do not turn aside from what I say.

8 Keep to a path far from her,
do not go near the door of her house,

9 lest you give your best strength to others
and your years to one who is cruel,

10 lest strangers feast on your wealth
and your toil enrich another man's house.

11 At the end of your life you will groan,
when your flesh and body are spent.

12 You will say, "How I hated discipline!
How my heart spurned correction!

13 I would not obey my teachers
or listen to my instructors.

14 I have come to the brink of utter ruin
in the midst of the whole assembly."

15 Drink water from your own cistern,
running water from your own well.

16 Should your springs overflow in the streets,
your streams of water in the public squares?

17 Let them be yours alone,
never to be shared with strangers.

18 May your fountain be blessed,
and may you rejoice in the wife of your youth.

19 A loving doe, a graceful deer—
may her breasts satisfy you always,
may you ever be captivated by her love.

20 Why be captivated, my son, by an adulteress?
Why embrace the bosom of another man's wife?

21 For a man's ways are in full view of the LORD,
and he examines all his paths.

22 The evil deeds of a wicked man ensnare him;
the cords of his sin hold him fast.

23 He will die for lack of discipline,
led astray by his own great folly.

But who will care about these words? Only those who obey the Lord's law and treasure it in their hearts. As the Psalmist says:

They are happy whose life is blameless,
who follow God's law!
They are happy who do his will,
seeking him with all their hearts,
who never do anything evil
but walk in his ways.

Follow these words and you will be happy in this life and in the next. Amen! Alleluia!