Islam is a sect, not a religion, Europe must ban this harmful ideology 聼起來自然嗎?

It sounds natural, but "sect" is probably not the word you want. "Sect" means that Islam is part of some larger religion. Lutheranism or the Coptic Church are sects. "Cult" might be better- that's a word people use when they don't want to respect a religion- but a cult is normally small enough to all meet in one room.