The Great Apostasy is a concept within Christianity, identifiable at least from the time of the Reformation, to describe a perception that the early apostolic Church has fallen away from the original faith founded by Jesus and promulgated through his twelve Apostles. Protestants used the term to describe the perceived fallen state of traditional Christianity, especially the Roman Catholic Church, because they claim it changed the doctrines of the early church and allowed traditional Greco-Roman culture (i.e.Greco-Roman mysteries, deities of solar monism such as Mithras and Sol Invictus, pagan festivals and Mithraic sun worship and idol worship) into the church on its own perception of authority. Because it made these changes using claims of tradition and not from scripture, the Church – in the opinion of those adhering to this concept – has fallen into apostasy. A major thread of this perception is the suggestion that, to attract and convert people to Christianity, the church in Rome incorporated pagan beliefs and practices within the Christian religion, mostly Graeco-Roman rituals, mysteries, and festivals. For example, Easter has been described as a pagan substitute for the Jewish Passover, although neither Jesus nor his Apostles enjoined the keeping of this or any other festival.