This is why the Church requires that those approaching marriage should be mature and serious enough to know what is involved in their commitment. In past times and centuries, when societies were heavily structured and even dictated human affairs, it was almost impossible to leave a marriage once it was entered into. Divorce was rare and such a social stigma that very few sought it. In the past marriages were often arranged by the bride and groom's parents and people got married at a very young age. However, in recent decades the social fabric in the United States has unraveled.
Society provides little or no safeguards in support of marriage.
People do not often think in terms of life-long commitment. Many enter into marriage with the thought that if things do not work out, they can always get a divorce. Also, in a rapidly changing world, commitments made in one's youth are considered difficult to fulfill as time goes on. In other words, since God is true to His promises, and since God recognizes the burdens and difficulties of married life, God will provide all the grace to fulfill one's responsibilities in marriage providing we wish to cooperate with God. A Christian marriage gets into trouble either because the two parties should not have gotten married in the first place, or because one or both parties in the marriage are not cooperating with God's grace because of their own moral failure.