Although to some they may seem like the good side of humanity, they have done some horrible things from trying to wipe out religions to even an entire race. Take the crusades as an example.
The Crusades were motivated by Christian beliefs which led to the deaths of many millions of people in the first 4 crusades with more added when the others happened. All for what? To reclaim an area of land which they see as theirs, their holy land. This land was also the holy land of other religions such as the Jews.
There is also the use of Hitler as an example, although he said that Christian beliefs were a part of his campaign and reign, they seem overly similar to the ones that are of the crusades. This again lead to the persecution of the Jews and millions of lives lost.
Still think that the Catholic Church is good? You sure it hasn't corrupted people?