Lumen Gentium, the most important constitution of Vatican II, marks 60 years since its promulgation on November 21, 1964. As noted by theologian C. O’Donnell, it is the most significant document of the Second Vatican Council. This constitution defines the Church more clearly, responding to Pope Paul VI's call. It provides essential insights into ecclesiology, contributing to a better understanding of what the Church of Christ is. Over the past 60 years, Lumen Gentium has served as a foundation for various authors' works. The constitution is structured into eight chapters, guiding the reader uniformly to the nature of the Church of Christ and its destiny in the world. The first chapter discusses the Church's mystery in the salvific plan of God. The second chapter presents the "place" prepared by the Lord for salvation through the people of God throughout history. The third chapter outlines the hierarchical composition of this people, including bishops, priests, and deacons, while the fourth chapter addresses the common priesthood of all baptized, including laypeople. Chapter five discusses the universal call to holiness within the Church, and chapter six addresses religious life, emphasizing the evangelical virtues. The constitution emphasizes the Trinity's ecclesiology, leading readers to continuous reflection. Lumen Gentium presents the Church as a flock with Christ as the gate and shepherd, a field of the agricultural Jesus, a temple with Christ as the cornerstone, and a house of God where the Lord is part of our family. The Church is described as the "celestial Jerusalem," with its kingdom "already and not yet" arriving. The Church is both visible and invisible, composed of the visible Church (hierarchy, religious, and laypeople) and the invisible Church (all baptized, forming the mystical body of Christ). The Council also emphasizes the importance of ecumenism and interreligious dialogue, highlighting the Church's missionary action. Finally, the constitution concludes by urging the faithful to imitate the Virgin Mary, the Mother of God and the Church. The Church, as the people of God, is united to Christ, as emphasized by Ratzinger. Theology and ecclesiology are inseparable, with God's action creating the "people of God," who become the "body of Christ" through Christ. This is reflected in Paul's interpretation of Abraham's promise. Deepening knowledge of the Church deepens our union with Christ, the light of the peoples.Lumen Gentium, the most important constitution of Vatican II, marks 60 years since its promulgation on November 21, 1964. As noted by theologian C. O’Donnell, it is the most significant document of the Second Vatican Council. This constitution defines the Church more clearly, responding to Pope Paul VI's call. It provides essential insights into ecclesiology, contributing to a better understanding of what the Church of Christ is. Over the past 60 years, Lumen Gentium has served as a foundation for various authors' works. The constitution is structured into eight chapters, guiding the reader uniformly to the nature of the Church of Christ and its destiny in the world. The first chapter discusses the Church's mystery in the salvific plan of God. The second chapter presents the "place" prepared by the Lord for salvation through the people of God throughout history. The third chapter outlines the hierarchical composition of this people, including bishops, priests, and deacons, while the fourth chapter addresses the common priesthood of all baptized, including laypeople. Chapter five discusses the universal call to holiness within the Church, and chapter six addresses religious life, emphasizing the evangelical virtues. The constitution emphasizes the Trinity's ecclesiology, leading readers to continuous reflection. Lumen Gentium presents the Church as a flock with Christ as the gate and shepherd, a field of the agricultural Jesus, a temple with Christ as the cornerstone, and a house of God where the Lord is part of our family. The Church is described as the "celestial Jerusalem," with its kingdom "already and not yet" arriving. The Church is both visible and invisible, composed of the visible Church (hierarchy, religious, and laypeople) and the invisible Church (all baptized, forming the mystical body of Christ). The Council also emphasizes the importance of ecumenism and interreligious dialogue, highlighting the Church's missionary action. Finally, the constitution concludes by urging the faithful to imitate the Virgin Mary, the Mother of God and the Church. The Church, as the people of God, is united to Christ, as emphasized by Ratzinger. Theology and ecclesiology are inseparable, with God's action creating the "people of God," who become the "body of Christ" through Christ. This is reflected in Paul's interpretation of Abraham's promise. Deepening knowledge of the Church deepens our union with Christ, the light of the peoples.