Abstract
<jats:p>The book "Church and Churches", a result of the 16th international symposium organized by the Department of Ecclesiology at the Pontifical University of John Paul II, delves into the multifaceted issue of relationships between the universal Church and local churches, as well as the diversity of Christian denominations in the context of unity and ecumenism. The included articles explore theological, historical, and social dimensions of this relationship, addressing topics such as the catholicity of the Church, ecumenical challenges, and anti-ecumenical trends in Orthodoxy. Contributions from theologians of various Christian traditions, including analyses of "sister Churches" and reflections on the mystery of Ecclesia, emphasize the effort to understand diversity within unity. This publication provides a valuable contribution to the debate on the contemporary understanding of the Church and its mission in the world.</jats:p>