The Church seeing large families as a sign of God 's blessing . " 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 find its crowning glory . " ( Gaudium et spes ) Children are the supreme gift of marriage and contribute greatly to the good of the parents themselves . ( ... ) true married love and the whole structure of family life which result 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 . ( Gaudium et spes ) . " It recognize that responsible parenthood sometimes call for reasonable spacing or limiting of births and consider natural family planning as morally acceptable , but reject all methods of artificial contraception . The Church reject all forms of artificial insemination and fertilization because the techniques divorce the sexual act from the creation of a child . The Catechism state , " A child is not something owed to one , but is a gift ... ' the supreme gift of marriage . ' "