The fallen state of traditional Christianity, especially the Roman Catholic Church, because they claim it 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. In short, in their opinion, the church has fallen into apostasy. They feel that to attract the pagans to nominal Christianity, the Catholic Church took measures to amalgamate the Christian and pagan festivals so pagans would join the church; for example, bringing in the pagan festival of Easter as a substitute for the Pasch or Passover, although neither Jesus nor his Apostles enjoined the keeping of this or any other festival
Constantine the Great (c. 325 AD) merged paganism with Christianity, seeking to bring unity and stability under his rule, and advance acceptance of and
the power of the church by all sectors of the empire. However, this
had a corrupting effect on the beliefs of the church and through decades of succession by poor, often politically motivated leadership, abuses of scriptural application became prevalent.
Great Apostasy