They never left the Church. The Protestants did.
The Protestants left a Satanic organization led by the second sons of European aristocracy in the Middle ages. Simony. Pluralism. Buy an indulgence to save your soul and help me build an edifice to my own honor while the people starve. Sorry, it was Satanic. At least today you can see some areas where Rome cares about the people. Corrupt Pope after corrupt Pope had sickened the European church and God. And like the Israelites out of Egypt- the Protestants left.
The church is Christ's body made up of all believers. And, like it or not, MANY Protestants will be in heaven and many Catholics in Hell. It's not what is over the door, its whether or not you have a relationship with Jesus Christ.