Is the present-day Roman Catholic Church the same church on which it was founded? Is the present-day Roman Catholic Church the same church on which it was founded? The Roman Catholic Church holds that the first pope was St. Peter, and his burial became the St. Peter's Basilica. If I remember correctly, National Geographic Inside the Vatican seems to support the idea that the first pope was St. Peter. Anyway, is the present-day version of the church the same church on which it was founded? In what ways has the church changed or modified to deal with the times?

The obvious:


Different popes
Different worldly events
Different cultures


Doctrinally, how is the present-day Roman Catholic Church the same or different from the one led by the first Pope in Rome?
Is the present-day Roman Catholic Church the same church on which it 
  was founded?


The shortest and simplest answer is: yes.

The longer and significantly more complex answer would fill many volumes of an encyclopedia.

But, to very briefly scratch the surface...

The Church maintains that, although her fundamental doctrine hasn't changed, it has developed over the centuries.

Catholic apologists compare the Catholic Church's growth and development to that of an acorn. An acorn, in its smallest and simplest form, is genetically the same as a 200 year old Oak tree. An acorn looks nothing like an Oak, even though it fundamentally has everything it needs to grow and develope into a giant 200 year old tree.

In the same way the early primitive Church and her depositum fidei was planted by Christ through Holy Spirit. Of course the Church had to grow and develope in order to preach the Gospel to all nations. 


  The 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, 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) 


Over time the Church has developed various doctrines and dogmas that aren't explicitly displayed in Sacred Scripture. Some examples are the doctrines of the Trinity, the Incarnation, and the Hypostatic Union. These doctrines are fundamental to the Faith, yet haven't always been as clearly defined as they are now. 

Most of the Church's development of doctrine has been brought on by the assaults of heresies such as Arianism and Monothelistism. Various councils and synods have been called to develope these crucial doctrines in order to protect her fundamental truths.

See: DENZINGER

Finally, its important to distinguish between the true teachings of the Church and the abuse of the teachings of the Church. Many Christians have been scandalized by false representations of the truths of what the Church teaches. 

Martin Luther posted his 95 theses primarily because the Church's indulgences were being fraudulently abused.  The true purpose of the granting of indulgences is simply to help Catholics grow in holiness, but millions of people have been scandalized because the abuses of men like Johann Tetzel.

The same goes for marriage. Marriage is, by definition, a holy and righteous sacrament institiuted by Christ.  Millions of people are scandalized everyday because marriage is abused.


  The abuse of a good does not diminish the good of a good.
  (Matthew Kelly, Rediscovering Catholicism)