Superssessionism is the idea that one religion was true but that it stopped being true after another religion showed up to supersede it. For example, Christianity believes that Judaism was true once but that because the Jews rejected Jesus they stopped being the Chosen People and that the New Testament and a faith-based religion replaced Jewish Law. Islam also believes that God gave the Torah (or something similar to it) to the Israelites at Mount Sinai but that the Quran ultimately replaced it.