Pope John Paul gets a reference in his approval of inculturation as a principle of liturgical reform:
2. In his apostolic letter Vicesimus Quintus Annus, the Holy Father Pope John Paul II described the attempt to make the liturgy take root in different cultures as an important task for liturgical renewal.[cf. no, 16] This work was foreseen in earlier instructions and in liturgical books, and it must be followed up in the light of experience, welcoming where necessary cultural values “which are compatible with the true and authentic spirit of the liturgy, always respecting the substantial unity of the Roman rite as expressed in the liturgical books.”[cf no. 16]
Lived experience with the liturgy must be applied to reform. In other words, if liturgical aspects work or don’t work for the cause of evangelization, they must be applied. Faith and belief should always trump the particulars of liturgy.
At the same time, John Paul wants the substance of the Roman Rite to remain as a substrate. That is where the discussion and occasional tussling occur. What is the substantial unity of the Roman Rite? Certainly the seven sacraments and the structure of their liturgies. Some might say translations, but I wouldn’t–and I wouldn’t be alone.
What would you readers see as areas of “substantial unity” and what can be adapted for the sake of belief?