Interpersonal Relationships in Islam and Christianity concludes the series The Family Institution in Islam and Christianity by extending the discussion beyond the immediate and extended family to the broader sphere of human interaction within society. While the earlier volumes examine specific roles and relationships within the family structure-such as those of parents, spouses, children, and relatives-this final volume explores the ethical principles that govern interactions between individuals in the wider social environment. Drawing from the sacred scriptures of the two traditions-the Qur'an, Hadith literature, and the Bible-the book presents a comparative study of the moral teachings that guide human conduct toward others. It explores themes such as mutual respect, compassion, justice, honesty, cooperation, and responsibility, demonstrating how both Islam and Christianity place profound emphasis on maintaining dignity, fairness, and kindness in dealings with others. The work highlights that healthy societies are built not only upon strong families but also upon ethical interpersonal relationships rooted in moral accountability and spiritual awareness. By examining scriptural teachings from both faiths side by side, the book reveals the shared ethical vision that underpins Islamic and Christian perspectives on human interaction. As the concluding volume of the series, Interpersonal Relationships in Islam and Christianity completes a comprehensive exploration of the moral architecture of family and social life. It demonstrates that the values governing family relationships naturally extend to society at large, forming the basis of harmonious communities and responsible human coexistence. Thoughtful and accessible, this work serves as a valuable resource for students of religion, scholars of comparative ethics, and readers interested in the enduring moral principles that guide relationships within both family and society.