Many religious groups often supply scripture and reading material, organize programs and worship, and train
chaplains for work in prisons. Members of religious groups also engage in missionary activity, as there have been many instances of conversion throughout history. For instance, one of the earliest introductions of
Islam into
Eastern Europe was through the work of an early 11th-century Muslim prisoner who was captured by the
Byzantines during their war against Muslims. The Muslim prisoner was brought into the territory of the
Pechenegs, where he taught and converted individuals to Islam. In the United States, early
colonists originated the concept of the
penitentiary as a place where inmates would demonstrate their
penance and remorse for their crimes through prayer and reflection. English prison chaplains also heard confessions from condemned prisoners, some of which were published – for example, the 18th century ''
Ordinary of Newgate's Account''. Such accounts presented the prisoners as coming to terms with their guilt and preparing for salvation. Chaplains have worked with prisoners and prison staff for many years, even before formal legislation addressed the constitutional rights of inmates. A 2005
Journal for the Scientific Study of Religion study suggests that the practice of religion significantly reduces the chance of prisoners to engage in verbal or physical
altercations, and increases the likelihood of reform after completing prison sentence time. ==Reasons for religious involvement==