This blend of adaptability and immutability is often misunderstood. “If the church allows Fr Longenecker–a married man to be ordained, why can’t the church allow women priests?”
Because one is a discipline which can be changed. The other is a doctrine which cannot be changed.
“If the church allows the Novus Ordo Mass to be instituted why does she not allow divorced and remarried people to come to communion? Surely the church will change in time on these matter.”
Those who look for Pope Francis to make great changes need to stop and do their homework and realize what can be changed and what cannot be changed.
Once that is understood, and once it is understood that the things that cannot be changed are immutable by the very nature of their structure and nature then more people will understand why the Catholic Church does not change very much. The things that cannot be changed are the things which we consider to be revealed by God either through the Scriptures, the teaching of the church or directly through the teaching and example of Jesus Christ the Lord.
Those things–like the ten commandments, the creed and core doctrines, the nature of the sacraments simply cannot be changed because we didn’t make them up to start with. They were given to us by God. Because they were given and not made by us we can’t change them. Attempting to change them would be like attempting to change physical reality or historical facts. Certain things simply exist and really happened and no amount of words games or head games will change them, and even if you succeeded in making everyone change that thing it would still not be changed.
A ball is round not square and you may legislate that the ball is square, you might write it into every textbook. You might forbid anyone from referring to a ball as “round”. You might make employees of the state issue documents stating that balls are square. You might change the liturgy of the church to thank God for square balls. You might teach every school child that a ball is square.
It will still be round.
So it is with Catholic doctrine and dogma. It can’t be changed even if we want to.
Catholic discipline and devotion, however can be altered and adapted and the balance of these two is what has allowed for the church to be ever ancient and ever new and to have lasted for 2,000 years and will last for another 2,000 if her Lord does not first return in glory.