The Church professes itself as "one" for several reasons:1. **Unity of Faith**: The Church believes in one unified set of doctrines and teachings based on the Bible and the tradition of the apostles, reflecting a shared belief system among all its members.2. **Unity of Leadership**: The Church is united under one spiritual leadership, traditionally symbolized by the Pope in the Roman Catholic Church, maintaining a common authority to guide and preserve its teachings.3. **Unity in Worship and Sacraments**: The Church practices shared worship through the same sacraments, especially the Eucharist, which symbolizes the oneness of the body of Christ that all believers participate in.