It's not uncommon to hear people, especially in the media, speculate about when or if the Catholic Church is going to change one teaching or another. As the upcoming Synod on Synodality approaches in Rome, such discussions are especially common. Some progressive Catholics seem to await such change with bated breath, while some conservative Catholics wring their hands with concern. When trying to understand whether Catholic teaching can "change," here are five important things to know: 

1. The Church is a servant of what God has revealed.

Catholic teaching is not simply made up by the pope or a panel of bishops, but is rooted in the Word of God, or "divine revelation," which is handed on to us in Sacred Scripture and Sacred Tradition. The pope and bishops have a divine authority to teach, guard, and interpret the Word of God, but they cannot change or add to what God has revealed. The Second Vatican Council explained in 1965: 

Sacred tradition and Sacred Scripture form one sacred deposit of the word of God, committed to the Church. Holding fast to this deposit the entire holy people united with their shepherds remain always steadfast in the teaching of the Apostles, in the common life, in the breaking of the bread and in prayers (see Acts 2, 42, Greek text), so that holding to, practicing and professing the heritage of the faith, it becomes on the part of the bishops and faithful a single common effort. 

But the task of authentically interpreting the word of God, whether written or handed on, has been entrusted exclusively to the living teaching office of the Church, whose authority is exercised in the name of Jesus Christ. This teaching office is not above the word of God, but serves it, teaching only what has been handed on, listening to it devoutly, guarding it scrupulously and explaining it faithfully in accord with a divine commission and with the help of the Holy Spirit, it draws from this one deposit of faith everything which it presents for belief as divinely revealed (Dei Verbum 10). 

In other words, Catholic teaching is always based on the truth that God has revealed, not on the opinions of the day.  

2. God's revelation was completed in Jesus himself.

God spoke to his people in various ways throughout biblical history, but the fullness of revelation came in the Person of Jesus himself, who is God-made-man. There will be no further revelation from God until Jesus comes again in glory: 

Jesus perfected revelation by fulfilling it through his whole work of making Himself present and manifesting Himself... The Christian dispensation, therefore, as the new and definitive covenant, will never pass away and we now await no further new public revelation before the glorious manifestation of our Lord Jesus Christ (Dei Verbum 4, see 1 Timothy 6:14 and Titus 2:13).

3. The Pope cannot proclaim "new" doctrines. 

In 1870, the First Vatican Council, based on Scripture and Tradition, taught that the pope teaches with "infallibility" - i.e., without error - when, by virtue of his office as successor of St. Peter, he proposes a teaching on faith or morals to be definitively believed by all of the faithful. The First Vatican Council offered this important clarification, however: 

For the Holy Spirit was promised to the successors of Peter not so that they might, by his revelation, make known some new doctrine, but that, by his assistance, they might religiously guard and faithfully expound the revelation or deposit of faith transmitted by the apostles (Session 4, Chapter 4, 6). 

In other words, the pope's authority exists only to hand on faithfully the truth of Jesus Christ to each new era, not to teach anything that would contradict what has been dogmatically taught in the past. The only person with the authority to say, "You have heard it said... But I say unto you..." (Matthew 5:21, 27, 33, 38) is Jesus Christ himself. 

4. Church teaching does develop in continuity with past Church teaching. 

Although the truths of the Catholic faith do not change, the Church's understanding of these mysteries does often deepen from century to century. Just as acorns always grow into oak trees, rather than suddenly becoming blueberry bushes, Catholic doctrine always develops in continuity with the past. Such development in understanding is to be expected as the world changes from century to century and as we confront new questions. The Second Vatican Council explained: 

This tradition which comes from the Apostles develops in the Church with the help of the Holy Spirit. For there is a growth in the understanding of the realities and the words which have been handed down. This happens through the contemplation and study made by believers, who treasure these things in their hearts (see Luke, 2:19, 51) through a penetrating understanding of the spiritual realities which they experience, and through the preaching of those who have received through Episcopal succession the sure gift of truth. For as the centuries succeed one another, the Church constantly moves forward toward the fullness of divine truth until the words of God reach their complete fulfillment in her (Dei Verbum 8). 

5. We need to read Church teaching through the lens of "continuity." 

The First Vatican Council emphasized that what we believe today must always be in continuity with what the Church has officially taught in the past: 

For the doctrine of the faith which God has revealed is put forward not as some philosophical discovery capable of being perfected by human intelligence, but as a divine deposit committed to the spouse of Christ to be faithfully protected and infallibly promulgated. 

Hence, too, that meaning of the sacred dogmas is ever to be maintained which has once been declared by Holy mother Church, and there must never be any abandonment of this sense under the pretext or in the name of a more profound understanding. (Dogmatic Constitution on the Church, Chapter 4, 13-14). 

If the Church teaching today can simply un-teach what has been authoritatively taught in previous centuries, then the teaching authority of the Church is meaningless. After all, if a pope today can simply reverse what has been proclaimed by the popes and Ecumenical Councils of the past, why should we bother listening to any pope or Council today? Can't we just expect that a future pope will come along to make faith and morals more consistent with our own personal preferences?

Accordingly, we should not think that the pope or bishops can simply undo the Catholic teaching of the past. Dispelling concerns about the upcoming Synod on Synodality, our apostolic nuncio Archbishop Christophe Pierre recently reaffirmed that the synod is not about changing doctrine, but is about working together at all levels to listen to one another and to the Holy Spirit. (That doesn't mean, however, that some leaders aren't pushing for reversals of Catholic teaching; we should continue to pray for the Synod and for all of the leaders of the Church.)

Rather than imagining that Catholic teaching can be changed according to our own preferences or even those of the pope and bishop, let us submit ourselves in faith to the unchanging truth of Jesus Christ, who is "the same yesterday, today, and forever" (Hebrews 13:8).