A - Thanks for the question! Vatican II is such an important subject because it is the foundation for everything that John Paul the Great and PB16 have done in their pontificates. They have both stated that their pontificates are meant to be the ones that put into action what Vatican II taught. So, as a Church we need to have a firmer grasp on what Vatican II was all about.
When John XXIII called the Council, the Church was in shock. 'Why' was the question.
John XXIII’s theme for the Council was put forward in a document to open the first session. (Gaudet Mater Ecclesia) “Mother Church Rejoices”. The Church is called to teach, govern and sanctify.
But, unlike most other councils of the Church, there was no crisis in doctrine that proceeded it. There was also no need for dogmatic definitions. What the Church needed was for to apply the teachings the Church already had to the present and foreseeable future.
So, he wanted the Church to examine itself and ask the question of “what do we need to do to make our faith deeper and more lively.”
There was a deep need to have doctrine stated in a relevant way, but in a way that did not change what was being taught. It's formulation and presentation needed updating without leaving any truth behind.
John XXIII's vision of the council was:
1 - Awareness - The Church is aware of itself
2 - Renewal - After we become aware we reform (note you cannot reform what you don’t know about)
3 - Dialogue - Dialogue with the world at large.
So, let me give some of the overarching themes in Vatican II.
1 - Universal Call to Holiness.
All are called to holiness. Everyone.
2 - Ressourcement – a recovery of the sources
An attempt to "recapture" some of the ancient practices/knowledge we lost through the years.
3 - Aggiornamento – Updating
Updating of what can be updating. Not a change of doctrine, but in presentation.
4 - Continue Liturgical reform
Liturgical reform started long before and continues long after Vatican II. So, it is still on-going and will be until we get it right. This is the most visible part of Vatican II.
5 - Call of the laity to reform the temporal order
Clergy don't work in the factories, offices and homes of families. This is where the Gospel needs to be.
6 - Evangelization of the world through dialogue/holiness/emphasizing human dignity.
Dialogue does not mean we leave the truth behind.
Some of the other topics in the documents include:
- social life
- political community
- moral basis of authority
- Eastern Rite Catholic Churches
- Office of Bishops
- Priestly formation
- Christian Education
- Non-Christian Religions Laity
- Religious liberty
I will tell you this. Some people did embrace modernity. But, that is certainly not what the Council called for.