Certain relationships are of profound importance for human life and of great significance for the moral life. In Friendship: A Study in Theological Ethics, Gilbert C. Meilaender explores some of the tension which Christian experience discovers in one such relationship, that of the bond of friendship. These tensions help to explain why friendship was a more important topic in the life and thought of the classical civilizations of Greece and Rome than it has usually been within Christendom.
 
The bond of friendship—philia--involves special preference; Christian love--agape--is thought to be like the love of the heavenly Father who makes his sun rise on the evil and the good and sends rain on the just and the unjust. Philia requires that love be returned; agape is to be shown even the enemy, who does not love in return. Friendships sometimes fade away; Christians are enjoined to be faithful in love. These tensions have permeated our lives and helped to shape our world, one in which politics is a more important sphere than the private friendship bond. We seek fulfillment in and identify ourselves with our vocations and not our friendships. And, in a world where politics and vocation are all-important, lasting friendships become more difficult to sustain. Friendship examines the tension between philia and agape and probes its significance for Christian thought and experience.