In his address to the U.S. Catholic bishops, Pope Benedict just delivered a strong message: it's your job to stand for, evangelize and educate on marriage: 

". . . In this regard, a matter of deep concern to us all is the state of the family within society. Indeed, Cardinal George mentioned earlier that you have included the strengthening of marriage and family life among the priorities for your attention over the next few years. In this year's World Day of Peace Message I spoke of the essential contribution that healthy family life makes to peace within and between nations. In the family home we experience "some of the fundamental elements of peace: justice and love between brothers and sisters, the role of authority expressed by parents, loving concern for the members who are weaker because of youth, sickness or old age, mutual help in the necessities of life, readiness to accept others and, if necessary, to forgive them" (no. 3). The family is also the primary place for evangelization, for passing on the faith, for helping young people to appreciate the importance of religious practice and Sunday observance. How can we not be dismayed as we observe the sharp decline of the family as a basic element of Church and society? Divorce and infidelity have increased, and many young men and women are choosing to postpone marriage or to forego it altogether. To some young Catholics, the sacramental bond of marriage seems scarcely distinguishable from a civil bond, or even a purely informal and open-ended arrangement to live with another person. Hence we have an alarming decrease in the number of Catholic marriages in the United States together with an increase in cohabitation, in which the Christ-like mutual self-giving of spouses, sealed by a public promise to live out the demands of an indissoluble lifelong commitment, is simply absent. In such circumstances, children are denied the secure environment that they need in order truly to flourish as human beings, and society is denied the stable building blocks which it requires if the cohesion and moral focus of the community are to be maintained.

As my predecessor, Pope John Paul II taught, "The person principally responsible in the Diocese for the pastoral care of the family is the Bishop ... he must devote to it personal interest, care, time, personnel and resources, but above all personal support for the families and for all those who … assist him in the pastoral care of the family" (Familiaris Consortio, 73). It is your task to proclaim boldly the arguments from faith and reason in favor of the institution of marriage, understood as a lifelong commitment between a man and a woman, open to the transmission of life. This message should resonate with people today, because it is essentially an unconditional and unreserved "yes" to life, a "yes" to love, and a "yes" to the aspirations at the heart of our common humanity, as we strive to fulfill our deep yearning for intimacy with others and with the Lord." 

For the full text of Pope Benedict's message to the Catholic bishops, click here.

For a compendium of all Pope Benedict's statements on marriage, click here (PDF file).