All Souls' Day memorialize the all faithful departed souls. In Western Christianity, this day is observed principally in the Catholic Church. The Eastern Orthodox Church observes several All Souls' Days during the year. The Roman Catholic celebration is associated with the doctrine that the souls of the faithful who at death have not been cleansed from the temporal punishment due to venial sins and from attachment to mortal sins cannot immediately attain the beatific vision in heaven, and that they may be helped to do so by prayer and by the sacrifice of the Mass. The Western celebration of All Souls' Day is on 2 November and follows All Saints' Day.