"The Catholic Church has always seen itself as an organic whole, a society one, holy, catholic and apostolic, consisting of human beings united by the Faith, the sacraments and the Roman hierarchy. This Church is so much one, that no piece can be broken off or taken away without its ceasing to be Catholic (cf. Jn. XV, 4-6). For instance, that Faith which is the prime constituent of the Catholic believer cannot be held piecemeal, but must be held either altogether (at least implicitly) or not at all. This is because it is on the authority of God revealing the dogmas of Catholic Faith that I believe them, so that if I disbelieve only one amongst many dogmas, I am rejecting his authority behind them all, in which case even if I believe all the other dogmas, my belief is resting no longer on God's authority but only on my own choice."
How can we claim unity, when Jesus is split into hundreds of denominations?
The point of the quote precisely.