In the light of these facts [about the nature of marriage and love] the characteristic features and exigencies of married love are clearly indicated, and it is of the highest importance to evaluate them exactly.
This love is above all fully human, a compound of sense and spirit. It is not, then, merely a question of natural instinct or emotional drive. It is also, and above all, an act of the free will, whose trust is such that it is meant not only to survive the joys and sorrows of daily life, but also to grow, so that husband and wife become in a way one heart and one soul, and together attain their human fulfillment.
It is a love which is total—that very special form of personal friendship in which husband and wife generously share everything, allowing no unreasonable exceptions and not thinking solely of their own convenience. Whoever really loves his partner loves not only for what he receives, but loves that partner for the partner's own sake, content to be able to enrich the other with the gift of himself.
Married love is also faithful and exclusive of all other, and this until death. This is how husband and wife understood it on the day on which, fully aware of what they were doing, they freely vowed themselves to one another in marriage. Though this fidelity of husband and wife sometimes presents difficulties, no one has the right to assert that it is impossible; it is, on the contrary, always honorable and meritorious. The example of countless married couples proves not only that fidelity is in accord with the nature of marriage, but also that it is the source of profound and enduring happiness.
Finally, this love is fecund. It is not confined wholly to the loving interchange of husband and wife; it also contrives to go beyond this to bring new life into being. "Marriage and conjugal love are by their nature ordained toward the procreation and education of children. Children are really the supreme gift of marriage and contribute in the highest degree to their parents' welfare."
Pope Paul VI, Humanae Vitae, 7-8
Reflection – Well, back to ‘weekends with Humanae Vitae’. The next three days we’ll read together through the next bit of the encyclical.
Here we see such a clear and beautiful presentation of what marriage is, the necessary pre-condition to discussing what can or cannot happen within a marriage. If you don’t know what a thing is, you cannot know what it can or cannot do—agere sequitur esse is the philosophical principle here—doing follows from being, what a thing is determines what its right operation is.
The previous paragraph had rooted this esse of marriage in its reflection of the love of the Father for his creation and for the human person, and the love of Christ for the Church. Marriage in the natural order is an echo of God’s ‘it is very good’ to creation; marriage in the supernatural order manifests and in fact expresses the union of God and humanity that is the mystery of Christ the Bridegroom and his Bride the Church. And in this expression man and woman receive grace to live out the communion of love to which they are called.
It is because marriage is these things, because a validly contracted marriage of two baptized people is this, whether they are saintly paragons or utter messes or like 99% of us, a jumbled mix of both, that the ‘laws’ of marriage are what they are.
Marriage cannot be broken, because God’s covenant of love cannot be broken, God cannot stop loving his creation, Christ cannot ‘divorce’ the Church. Divorce is impossible, and no human laws can change that—this is the plain and unequivocal teaching of Christ himself in the Gospels. To ask the Catholic Church to change its laws to allow divorce and remarriage is to ask the Catholic Church to renounce Jesus Christ.
Marriage is exclusive and total, because that is who God is, who Jesus is. Infidelity in a marriage is a direct denial of the very nature of marriage.
And marriage is fruitful, ordered towards fruitfulness, because God’s love is creative, Christ’s love for us is fruitful within us. God’s love gives life; the expression of human love which most intimately corresponds to God’s love, which is nuptial sexual expression, must conform to the pattern of love to which it is made. And it must conform to it according to a fully human way of being and acting—in other words, in freedom, rational choice, and the deeply human decision to move in trust and in communion with one another and with God.
All of this is not just a bunch of arbitrary rules, but flows directly from the reality of what marriage is, revealed by God, revealed by Jesus Christ, and communicated to us through the Tradition of the Church. Agere sequitur esse – what a married couple does flows from who they are. Or as Pope St. John Paul II put it—families, be what you are!