First of all, I will begin with three true accounts of what prisons are like outside of North America and Western Europe. I am indebted to the Voice of the Martyrs and Amnesty International for these stories.
- In Eritrea (neighbour to the East African nation of Ethiopia), prisoners are tortured through beatings with iron bars. They are housed in unventilated metal shipping containers that are frigid at night and sweltering hot during the day. There are no hygiene facilities and the food provided is both unsanitary and inadequate (two breads and dirty water) 
- In the Chinese capital of Beijing, at the Haidian Detention Centre, prisoners are interrogated cruelly and without the advocacy of a lawyer. Shi Weihan was stripped of his clothes and placed against the wall outdoors in winter time. His handcuffed wrists were placed behind his neck and hooked to the wall. Electric shock batons were used on him as well as cold water for hours at a time.
- In the country of Iran in April 2014, prisoner Farshid Fathi had his foot broken by a guard who stomped on it with his heavy boot to stop him from aiding a fellow inmate who had been beaten. For three days he was denied medical treatment or any relief of pain. 
Then from history classes, we are also aware of various regimes who have established labour camps where prisoners are forced to do back-breaking physical work for 10-12 hours a day with little in terms of nourishment. Prisons in England up until the late 1800's were rampant with sickness, overcrowding and filth.
What brought about more humane conditions in prisons throughout England and its colonies? The influence of two Christian people, who put their faith into action.
1) John Howard (1726-1790) lived in England and experienced first-hand the prison conditions in France when the merchant ship he was on was captured by a French privateer. At the age of 47 he was appointed High Sheriff of Bedfordshire, becoming responsible for its prison. When he saw conditions there, he felt compelled to investigate prisons throughout England, Scotland and Wales. He wrote and published detailed and factual reports alerting British society and government for needed reforms. It took some time for his reforms to be accepted, but he continued to advocate for prisoners and tried to visit other countries in Europe to do so. According to the biography included on the website of The John Howard Society of Canada, Howard had the following priorities:
"Clean, healthy accommodation with the provision of adequate clothing and linen; segregation of prisoners according to sex, age and nature of offence; proper health care: these were his priorities. There should be a Chaplain service because he was of his age in believing that spiritual starvation was a major obstacle to reformation of character. Finally, he was a firm believer in the work ethic and the need for prisoners to be provided with work in order that the sin of idleness could be combatted." 
John Howard was motivated by his religious beliefs, rooted in Calvinism and the compassion of Christ for the suffering. In the same year of Canada's founding (1867), the John Howard Society of Canada formed with a group of Christians ministering to prisoners with spiritual help. Interestingly, the biography of its namesake that appears on the society's website goes out of its way to distance itself from his narrow-minded views and insults Howard's ideal prison as "a hygenic and well-run zoo."
2) Elizabeth Fry (1780-1845) was a Quaker. This Christian group was active in social causes and were strong pacifists. Fry began to be an unlikely leader at the age of 12 when her mother died and household responsibilities fell to her. When older, she led literacy classes for children who could not afford to attend school and also preached in her church.
After visiting prisons in Northern England and Scotland, Fry recognized that in the current situation, any prisoner that would eventually be released would be no better than when he or she was arrested. No attention whatsoever was given to rehabilitation. Some of her ideas were to instill self-respect in prisoners by giving them responsibilities, education and meaningful work to do. She had opportunity to testify at a House of Commons committee inquiring into prison conditions. By raising an issue that many chose to ignore, Fry was instrumental in setting new standards of humane treatment of the imprisoned.
Local Elizabeth Fry Societies have been established in Canada starting in Vancouver in 1939 to specifically assist women who have found themselves in trouble with the law.
I go into a Canadian federal prison for women almost every week. I see that there are still areas to improve, but when I compare the living conditions to what they have been in the past and what they are elsewhere in the world, I see the blessing of Christians who dared to advocate for criminals. Without the teachings of Jesus being taken seriously by John Howard and Elizabeth Fry and without their courage to speak up, our penal system in the West would be unrecognizable.
 Click on the highlighted words for full article from Amnesty International
video interview with Shi Weihan
 More information about Fathi's time in prison can be found here
The full biography can be found here