Louis Pasteur (Dec. 27, 1822-Sept. 28, 1895) was a French chemist and microbiologist. He is most famous for inventing the process that keeps milk from going sour, which is now known, in his honor, as pasteurization. He also performed experiments that confirmed the germ theory of disease, created the first rabies, anthrax and chicken cholera vaccines, was a founder of bacteriology and made numerous discoveries in chemistry. Pasteur described on a scientific basis the process of fermentation, wine-making, and the brewing of beer. "He debunked the widely accepted myth of spontaneous generation, thereby setting the stage for modern biology and biochemistry." 
Pasteur was also the Dean of the faculty of sciences at Lille University. He founded on June 4, 1887 the Pasteur Institute, a French non-profit private foundation dedicated to the study of biology, a forefront of the battle against infectious disease.
Resistance to his ideas
- Pasteur met with violent resistance from the medical men of his time when he advanced his germ theory. 
Discovery of vaccination
Coming back from a long vacation, he used cultures of disease-causing anthrax bacteria in an attempt to make more (in live birds), but the birds didn't get sick.
Science and religion
Pasteur was a devout Christian, and did not see any conflict between science and Christianity, remarking that "a bit of science distances one from God, but much science nears one to Him." Pasteur experienced many hardships throughout his life, including the death of three of his five children to childhood diseases including polio, but these hardships only served to strengthen his faith and his determination to find cures. Through it all Pasteur gave God the glory, stating that "the more I study nature, the more I stand amazed at the work of the Creator."
If one were to choose among the greatest benefactors of humanity, Louis Pasteur would certainly rank at the top. (Ibidem)
Chance favors the prepared mind.
Science knows no country, because knowledge belongs to humanity, and is the torch which illuminates the world. Science is the highest personification of the nation because that nation will remain the first which carries the furthest the works of thought and intelligence.
Let me tell you the secret that has led me to my goal. My strength lies solely in my tenacity.
A bit of science distances one from God, but much science nears one to Him."
The more I study nature, the more I stand amazed at the work of the Creator.