What is the theme in Gift from the Sea by Anne Morrow Lindbergh?

Marriage and relationships are important themes in the book. The author holds marriage in high regard. There is a deep belief in the tradition of marriage and the responsibilities and obligations it brings. The continuity of a relationship through marriage is one of the few things that does not change as the union progresses. The relationship of marriage changes with the first piece of property, the first house, the jobs of one or both parties. Still, those joined in marriage often desire the union to be as it was on the first day, before encumbrances present themselves and pressures take away time from the couple's small universe.