Choose from the list below on which event negatively effected the RC Church the most throughout it's  two thousand year history and give a reason why.

Or you can add your own, but again, explain why.

1. The Arian Heresy.

2. The birth of Mohamed.

3. The Great Schism of 1054.

4. The Crusades.

5. The Renaissance.

6. The fall of Constantinople to the Muslims Ottoman Turks in 1453.

7. Martin Luther nailing his 95 theses to the Church door at Wittenburg.

8. The French Revolution.

9.The October revolution in Russia in 1917

10..Vatican II ( 1962-65) and all it's liberal interpretations.

Vatican II.

And by a very long way.

Some of the other things on the list were attempts to destroy the Catholic Church.

However, Vatican II was an attempt that (in appearances, at least) has nearly succeeded,

but we know from Our Lord's own words that the Church will never be destroyed.

My order is as follows, starting with the worst:

10 (Vatican II)
8 (French Revolution)
3 (Great Schism)
7 (Luther and the Protestant Reformation)
1 (Arian Heresy)
2 (Birth of Mohamed)
9 (October Revolution in Russia in 1917)
6 (Fall of Constantinople)
5 (Renaissance)
4 (Crusades)

Vatican II was the worst because is the most destructive inner blow to the Church. The Reformation and French Revolution were both attacks from the outside.

Choose from the list below on which event negatively effected the RC Church the most throughout it's  two thousand year history and give a reason why.

For the almost-destruction of the Church, I believe the key event is Luther in 1517.

He liberalised i.e. cut man from God's Church. Once emancipated, man liberalised i.e. cut himself from God. Maybe we can say 1517 was the birth of the official liberalism?


Well, Luther didn't came out of nowhere. The failure and weakness of us catholics enabled him. Still he's been the tin opener for European liberalism, and hence for more, like :

- 1534, former Defensor Fidei (Defender of the Faith) Henry VIII deforms the catholic United Kingdom to the Lutheran sect named "Anglican Church", which also provides the basis for the protestantism of the subsequent USA.

- 1789, French Revolution, the zenith of the European liberalism (liberté blah-blah). It  starts the deformation of most of continental Europe to an anti-christian continent, going on until today.

- 1914, the liberalised and hence fatal weakened Europe is drawn into World War I. It crushes Central Europe's Christian empire Austria-Hungary, the Church's protecting power (*). It also crushes the Russian empire, which is schismatic but Christian in some aspect, and once this obstacle is removed, Lenin can drive forth the Scourge of God aka  the Jєωιѕн Communism, see Fatima. (Trotsky brings the international communism to USA...)

- 1965, V2 the Lutheran-ising of the now unprotected Church. Archbishop Lefebvre called it the (spiritual) World War III.

- 2012, Possible fall of one of the last and largest bastions of resistance, the SSPX

- 2013? Chastisement & Reconquista!



(*) For example the Austrian Emperor in 1904 vetoes against the liberal Cardinal Rampola to become pope, which gives us one last blessed pontificate: Sanct Pius X. Ironically the very humble pope didn't like this veto.
It's a sign of our times that in 500 years there's only two saint popes: Pius V and Pius X.

Ethelred said:

1534, former Defensor Fidei (Defender of the Faith) Henry VIII deforms the catholic United Kingdom to the Lutheran sect named "Anglican Church", which also provides the basis for the protestantism of the subsequent USA.

Correction:
The United Kingdom of Great Britain was founded in 1707. Henry VIII had nothing to do with the event.

Choose from the list below on which event negatively effected the RC Church the most throughout it's  two thousand year history and give a reason why.

Or you can add your own, but again, explain why.

1. The Arian Heresy.

2. The birth of Mohamed.

3. The Great Schism of 1054.

4. The Crusades.

5. The Renaissance.

6. The fall of Constantinople to the Muslims Ottoman Turks in 1453.

7. Martin Luther nailing his 95 theses to the Church door at Wittenburg.

8. The French Revolution.

9.The October revolution in Russia in 1917

10..Vatican II ( 1962-65) and all it's liberal interpretations.

The French Revolution and then eventually Vatican II because it is a culmination of Progressivism and the result of infiltration of the Church By the Modernists - Ultimately Vatican II is a result of the French Revolution which spawned Free Masonry , Modernist Philosophy - like "Hegelianism" which led to Communism and the Theory of Evolution and Widespread Atheism.

In case anyone was wondering My list is in chronological order, not necessarily from worst to first or vice versa.

I'd go with 7, 3, 8, 10, 2, 9, 1, 6, 5 in that order.

Not sure why you put the Crusades on that list.

I won't go through the reasons for all of them, but Luther was definitely the worst, by far. He got the ball rolling on private interpretation, and the supremacy of the individual conscience over objective truth.

Well, a few things went wrong during the Crusades IMO that really hurt the Western Church, including a sack of Constantinople  by the Crusaders I believe that left a real sour taste with the Byzantine Church and any hope of reunification with Rome any time soon after that.

Also, the way the Templars were sold out by the pope was not good for the Vatican in the long run with all kinds of theories where the surviving knights left their legacy, including Fɾҽҽmαsσɳɾყ. But that's another discussion.