In the sixth century, there was a big ecumenical council where leaders from across the Church got together and decided on various issues… there is an appendix with a list of curses against those who believe in Apocatastasis… The reason this is important—particularly if you’re a Catholic or Orthodox Christian—is if an ecumenical council declared universalism to be a heresy, then it is a heresy and that’s that.
—Robin Parry