Many religious books are open to interpretation, and disagreement about their meaning has often caused groups to break away from the traditional church. In the past, these people were called heretics or cultists, and their life expectancy was often short. Some groups moved far away to avoid persecution, but other groups stayed in their geographical area and hid their religious activities. They were generally successful at hiding unless a member betrayed them.
History tells tales of many religious organizations that split, and some of the more successful ones are still around today. Considered heretics and cultists in the past, the ones that attracted many people have become religions in their own right. Christianity has any number of branches from the original church, called Protestants, and they are more popular than ever. Many people find their lack of mysterious rituals, foreign languages and simplicity to be ideal, and this has encouraged small churches to grow into larger religious institutions.