The Catholic Church possesses its life and mission from the person of Jesus Christ, the risen Lord, who continues his saving work in every generation. Through the gift of the Holy Spirit, Christ calls men and women to holiness. The Holy Spirit uses many instruments to achieve this goal, including the witness of the faithful locally and throughout the world. It is the Holy Spirit who inspired the authors of Scriptures to write down the preaching of the apostles, who in turn, handed on the Word of God and its authentic interpretation through their successors. It is the Holy Spirit who continues the words and deeds of Christ in the preaching and sacraments of the church by which Christ continues to form for himself a holy people, his Body, the Church.
The interesting thing about our faith is that the basic truths never change. Our understanding of revealed truths may evolve and develop (such as the change in the Church’s understanding of slavery), but the fundamental principles never change. Catholics are called to be faithful to the words of Jesus, “Go, therefore, and make disciples of all nations…teaching them to observe all that I have commanded you” (Mt. 28:19-20). Because those principles are unchanging, Catholics are not free to “pick and choose” their beliefs. Rather, what makes us truly “catholic” (that is, “universal”) is our assent in faith to all that the Church professes, believes and teaches as “truth.”