Today we will consider what the Church calls the "goods of marriage." There is the good of a "...deeply personal unity, a unity that, beyond union in one flesh, leads to forming one heart and soul; it demands indissolubility and faithfulness in definitive mutual giving; and it is open to fertility." (1645)* Authentic love requires this unity. Love by its very nature is selfless and desires the good of the beloved. This love binds the spouses together inseparably and makes the marriage indissoluble.
Incorporated in conjugal love is the openness to fertility. The fruit of selfless love is the gift of children. Because love is not inward, it constantly goes outward. It is life giving. The husband and wife participate in God's creation with the advent of new life.
By its very nature the institution of marriage and married love is ordered to the procreation and education of the offspring and it is in them that it finds its crowning glory.
Children are the supreme gift of marriage and contribute greatly to the good of the parents themselves.... Hence, true married love and the whole structure of family life which results from it, without diminishment of the other ends of marriage, are directed to disposing the spouses to cooperate valiantly with the love of the Creator and Savior, who through them will increase and enrich his family from day to day. (1652)
The fruitfulness of conjugal love extends to the fruits of the moral, spiritual, and supernatural life that parents hand on to their children by education. Parents are the principal and first educators of their children. In this sense the fundamental task of marriage and family is to be at the service of life. (1653)
Spouses to whom God has not granted children can nevertheless have a conjugal life full of meaning, in both human and Christian terms. Their marriage can radiate a fruitfulness of charity, of hospitality, and of sacrifice. (1653)
Even when for some physical reason a couple cannot conceive a child, the love is such that it is still open to life. Artificial insemination and surrogate parenting are contrary to conjugal love and therefore wrong. However, the love of spouses can be shared through adoption if God is so leading the couple in this direction. This love always benefits society because it is always manifested in the desire to give of oneself for the good of others.
*Note: Numbers in brackets refer to the numbers assigned to paragraphs of The Catechism of the Catholic Church.