I’d feel angry, feel sad, amused.
I’d get angry because it is a blasphemy. We believe Jesus himself established the Church, and the Holy Spirit breathed life into it. So by saying that, it is like saying the Holy Spirit is the devil who established and breathed life into her. I wouldn’t want to be in the shoes of the people who say these on Judgment day.
I’d be sad because someone would only say something like this out of ignorance, or because certain people fed him/her false information. I would suggest taking a look at the Catholic Church in a historical perspective from unbiased sources.
I’m amused because it is incredibly silly. Didn’t Christ himself say we can tell from the fruits of the tree. The Church has the largest number of organizations that educate, feed the hungry, and care for the sick. No other umbrella organization can claim that. That doesn’t sound diabolical at all.
Sure individuals of the Catholic Church have done preposterous things. But the Church never said her members are perfect. In fact the Church admits that the individuals that make her up are sinners, which is why we in fact need the Church. What the hospital is to the sick, the Church is to sinners.