This theme emphasizes the importance of selflessness in marriage. The Kellers argue that true love is about serving your partner and putting their needs above your own. This perspective challenges the modern view of marriage as a means to personal fulfillment and instead highlights the joy and fulfillment that come from selfless love and service.

The concept of covenant is central to the Kellers' vision of marriage. They explain that marriage is not just a contract based on mutual benefit but a sacred covenant that mirrors the relationship between God and humanity. This theme underscores the importance of commitment and faithfulness, even in the face of challenges and difficulties.

The Kellers discuss the biblical concept of roles within marriage, advocating for mutual submission and respect. They challenge traditional gender roles and encourage couples to support and uplift each other. This theme promotes a partnership based on love, respect, and mutual support, rather than rigid roles and expectations.