Question: What if the ordination of women to the diaconate comes from the highest levels of the Catholic Church? What if the Pope says that this is okay? How should Catholics respond?
Answer: If the Pope were to approve this, he would commit a great fault, a serious mistake, and an error against the Catholic Church. This would be a heresy. In doing so, the Pope would betray his office. The bishops and the faithful cannot follow such a decision. They should not follow, and they must not follow a Pope who permits a female diaconate.
In such a case, we would have to resist the Pope. We must remain faithful to the divine order of the Church, which God Himself has given us. The Pope has no authority over this matter. He simply has no power to change what belongs to the divine constitution. If he believes he has that power, then he is mistaken.
And if he attempts to do this, I believe it would not last long. God would then grant us a new Pope who, with the highest authority, would formally condemn the heresy of a female diaconate. This could be done either through a future Council or by the Pope himself, because the Church is divine. And since she is divine, she will, in due time, condemn errors.
Dominus vobiscum. Et cum spiritu tuo.
Benedictio Dei omnipotentis, Patris et Filii et Spiritus Sancti, descendat super vos et maneat semper. Amen.