Let's see they help started the knights templar then after the crusades were over they back stabbed them but saying they were devil worshippers. They helped start the dark ages. They influenced the Holy Roman Empire on which person should next be King. Oh yeah after the schism instead of helping the city of Constantine they rather let the Muslims conquer it much of eastern europe.
While the Catholic Church has much to answer for over the course of the last millennium and a half, there are some gross historical inaccuracies in this post.
The Catholic Church did not found the Knights Templar. They were founded by a few knights in the Holy Land, and gained favor with the Church some time later. They were not controlled by or beholden to the Church - they were their own separate entity, and never an arm of Catholicism. The Templars weren't back-stabbed by the Church. They grew to a large and powerful organization based on the perception that they were God's Soldiers, blessed by him with the ability to keep the Holy Land safe for pilgrims. When the Holy Land was overrun by the Saracens, the Templars lost much of their clout. They were also heavily involved in usury in Europe to fund their organization, and King Phillip of France ended up owing them more money than he could repay. His solution was to declare them outlaws, seize their castles and absorb their wealth. He persecuted many of them, although it's debatable whether they deserved what they got. The demise of the Knights Templar had far more to do with Philip of France than with the Church.
The Catholic Church did not "help start the Dark Ages." The Dark Ages were a period of poverty throughout Europe, and while it is certainly true that the Catholic Church didn't give up its wealth to feed the poor, it is not true that they caused the Dark Ages, unless you believe the Catholic Church could create a mini Ice Age for a couple hundred years, or you believe they had some nefarious reason to do so. Now, could they have made it better? Absolutely. But they did not create it, nor did they sustain it. They profited by it by perpetuating the ignorance of the masses and thus keeping themselves in charge, but the same could be said of most every major and minor royal of the time, too.
The fall of Constantinople was as much political as it was a failure of the Catholic Church. The Church was heavily involved in politics at the time, and it is true that the Eastern Orthodoxy was in opposition to that of the West, whose seat was Rome, and this is entirely not in keeping with the teachings of Jesus that the Church claims to follow. Be that as it may, there is simply no historical accuracy to the idea that Muslims "conquered much of eastern Europe." I believe you're speaking of the Mongols, who were an unstoppable force as far as the West was concerned, and had the Mongols chosen to continue pushing West there is little or nothing The Church could have done to stop them.
The Ottoman Turks conquered Constantinople, but again this is a far more complicated situation than simply stating that The Church didn't help. The Eastern Empire was a shell of its former self, the Western Empire was as devastated by the effects of the Dark Ages and the Black Plague as the East, and it's unlikely, again, that had the western Church wanted to do anything to stop the Turks from conquering Constantinople that they could have. Medieval Europe simply wasn't capable at the time of resisting the Turkish forces as they conquered Constantinople.
Again, there's a lot of wrong to discuss with the Church over the years. But if we're going to discuss them, we should be as accurate as is reasonable.